Generators are fully customizable MIDI phrases, which can be variations of chord accompaniment (basic rock/pop piano), arpeggios (arpeggiator, fingerpicking, piano-style, or string-ensemble-style), or legato/monophonic (melodies, or basslines). In many of our Tutorial videos, we threw some Generators into our Composition, to get some quick ideas going with phrases and patterns.

Clicking the magic wand icon in the Phrase Inspector enlarges the window and shows all the parameters for the currently used phrase generator. All Generators have Rhythm Generator and Rhythm Processing options at the top.

The following phrase generators are included:

  • Arpeggiator: creates arpeggios from many types of patterns
  • Bass Generator: melody in a lower octave, resembling a bass guitar performance
  • Chord Generator: simple rhythms: quarter notes, half notes, whole notes, etc.
  • Dyads Run Generator: generates a MIDI run, commonly a “thirds run”
  • Fingerpicking Generator: guitar-style patterns/arpeggios
  • Generic Generator: piano-like patterns that can be easily manipulated rhythmically, based on a series of variables
  • Markov Melody Generator: experimental, generates melodies where the next note depends on previous notes. Not available in LE version
  • Melody Generator: generates melodies that intelligently fit over any chord or key. Not available in LE version
  • Modern Chord Pattern Generator: creates chord patterns used in EDM genre.
  • Ostinato Generator: generates ostinato patterns
  • Percussion Generator: generates percussion patterns using multiple percussion instruments
  • Phrase Container: arranges phrases using the selected order in the track
  • Phrase Morpher: intelligently connects 2 phrases or phrase generators by analysing them and generating the missing notes between the two phrases. Not available in LE version
  • Piano Chord Pattern Generator: creates a pattern for the left and right hand
  • Piano Run Generator: rhythmically rich arpeggios running up and down chords
  • Random Melody Generator: a simple but effective way of making surprisingly good melodies. Not available in LE version
  • Rest: Use only in the Idea Tool to inserts rests in the composition
  • Rhythm Mapper: maps a different rhythm pattern to a phrase (available only in the 'Convert Phrase To Generator' menu!)
  • Strings Staccato Generator: creates beautiful staccato patterns, perfect for orchestral and string quartet arrangements
  • Strum Pattern Generator: creates realistic guitar strum patterns with lots of options


Create simple or complex arpeggiated phrases with the Arpeggiator. As most other generators, the arpeggiator uses the rhythm generator which lets you create rhythmically complex, interesting arpeggiated phrases.

Arpeggiator Settings

  • Shape: there are lots of options for how the notes follow each other.
  • Key Range: describes the number of chord notes to be used
  • Retrigger: the arpeggiated pattern will be restarted at the 'retrigger' duration (quarter notes). 0 means the pattern never restarts.
  • Fill Between Notes: it is an interesting effect when you fill the space between arpeggiated notes with notes
  • Velocity For Filled Notes: velocity used for the added 'filler' notes

Bass Generator

The bass generator is a simple way of creating bass phrases. The specialty of this phrase generator that it can connect to the first note of the next phrase (it looks ahead).

Bass Generator Settings

  • Note Usage: There are many settings inside this drop-down, besides the default “Use Only Bass Notes”. Some of the other useful ones are “Use Bass Note+Fifth” or “Use Bass Note+Fifth+Octave”. Experiment!
  • Global Movement: Phrase shape. Available settings are Up (default), Down, Up-Down, Down-Up, Random, and Select Randomly.
  • Note Movement: Specify how successive notes relate to each other. Available settings are None (default), Alternating, Select Randomly.
  • Connection To Next Phrase: Available settings are None (default), One-Note, or Two-Note, Select Randomly.
  • Connection Movement: Available settings are Converge (default), Approach From Opposite Direction, Mixed/Random, Select Randomly.
  • Transpose (Octaves): Available settings are None, -1, -2 (default), -3, -4 Octaves.

We encourage you to experiment with the other Rhythm types for the Bass Generator. The Bass Rhythm is very useful, indeed, but you might want something different from your Bass Generator phrases. Notice how (after selecting the other Rhythm types) that all of the parameters might be similar, with slight changes to accommodate the legato and/or monophonic performance and playing style of bass instruments.

Chord Generator

The simplest phrase generator that fills all rhythm events with chord notes. Optionally you can add bass notes to the phrase a few octaves below the root note.

Chord Generator Settings

  • Add Bass Note: add bass note using octave transposition. Values: -1, -2, -3, -4 Octaves

Dyads Run

This generates a MIDI run, specifically by interval, commonly a “thirds run”, similar to the bridge of “Let It Be”, but could also be any interval, with polyphony option.

Dyads Run Settings

  • Motion: specify up or down motion
  • Interval: specify interval for the 2 notes. Possible values: Third (default), Fourth, Fifth, Sixth, Seventh, Octave
  • Polyphony: when required, the polyphony can be increased by inserting notes in octave distance from the original notes

Fingerpicking Generator

Most Generators have a rhythm Generator option at the top. The Fingerpicking Generator is one that doesn’t. The rhythm comes from the 'Speed' setting, which can be 1 or 2 events per quarter note.

Fingerpicking Generator Settings:

  • Speed: Available settings are Fast (default), Slow, or Travis Picking. Depending on how these are set, you’ll see the notes below change to be more “busy” or more “simple.”
  • Strings To Use: Lots of settings here. Don’t be afraid to experiment! Default is “Bottom 4 Strings.”
  • Add Pinch: Adding a pinch means plucking down another note at the same time you pluck down the bass note. When enabled, another note is allowed to play besides the bass note. Available settings are None (default), Once, Sometimes, and Always.
  • Sustain Notes: Note lengths increased so that notes last until the next note. Default setting is enabled, where the MIDI notes resemble fingerpicking an acoustic guitar.

Generic Generator

The Generic Generator lets you specify the proportion of chord/scale notes, the proportion of full polyphony/partial polyphony/monophonic notes, and note repetition options.

Generic Generator Settings

  • Chord/Scale Notes: 100% Chord Notes only use the notes from the chord in your Phrase, and other settings mix scale notes in.
  • Repeat Last: How often you’ll hear repeated notes back-to-back in your Phrase.
  • Repeat Second Last: How often you’ll hear notes repeat, though not back-to-back.
  • Full Polyphony/Monophony: Sets the percentage of notes that are played as full polyphony (all chord notes played together) or as a single monophonic note.
  • Allowed Partial Polyphony: Sets the amount of notes that can be played together when neither monophony nor full polyphony is used (2,3 or 4).
  • Note Selection Hints: Available “Include” settings are Bass Note, Chord Highest Note, Note Below Chord Highest, Note Above Chord Highest

Markov Melody Generator

This phrase generator must be enabled among the Settings / Miscellaneous / Experimental Features before first use. It is only for expert users because there are MANY settings that you should set up. Markov Melody is a monophonic phrase generator where each note depends on the previous two notes. You set weights (probabilities) with the sliders for all the scenarios that may happen. In the “Next Note” menu you can select from possible scale step offset for the next note compared to the last or second last note (depending on the scenario).

Markov Melody Generator Settings

  • Higher Than Both, Between, Lower Than Both, etc (possible scenarios for the next note): weight for this scenario
  • Next Note: scale step offset for the next note compared to the last or second last note (depending on the scenario)

Melody Generator

The Melody Generator is based on 'steps and leaps' and we at MusicDevelopments feel it is a great and incredibly useful addition to the full version of the program.

There are lots and lots of parameters to choose from and tweak, and you can get very usable results, in a very short amount of time!

Melody Generator Settings

  • Mode: Available settings are “Downbeat is always a chord note” (default), “Scale notes only (independent of harmony)”, “Downbeat and on-beat (1st & 3rd beat) is always a chord note”, “Chord notes only” and “Scale notes and chord notes”. Depending on how these are set, you’ll hear more “chordal” melodies, or more “scalar” melodies.
  • Options: Allowed up and down motion, and some other settings are here.
    • Penultimate note is a step above tonic: when set, the algorithm attempts to place the note before the last note to be a scale step about the chord root note
    • Allowed up/down motion: check which intervals are allowed for steps and leaps from one note to the other
    • Convert notes to 'chord note+scale steps' form: by default the Melody Generator creates scale-relative notes, but you can convert them to chord-relative
    • Allow 2nd to be a melody note: you can allow the 2nd to be a melody note even when using chord notes only. The 2nd very often participates in melodies.
    • Allow 7th to be a melody note: you can allow the 7th to be a melody note even when using chord notes only.
    • Don’t be afraid to experiment! Default settings are “Penultimate note is a step above tonic (also depends on the chord!)”, and nearly all “Allowed Up Motion” and “Allowed Down Motion” scale intervals are checked (except Octave motion).
  • First Note: Available settings are “Random chord note” (default), “Chord root note”, “Random scale note in note range”, and various absolute notes.
  • Last Note: Available settings are “Random chord note” (default), “Chord root note”, “Random scale note in note range”, and various absolute notes.
  • Climax: There are many settings here. The default Climax setting is “First Note plus Major 3rd”. You can also choose “No Climax”, or various scale interval movements. Experiment!
  • After Leap: This is the behavior that Melody Generator uses after notes “leap” (such as go up or down equal to or greater than a minor 3rd). The default setting is “Any step or leap (allow 2 leaps in the same direction)”. You can also choose “Step in the opposite direction”, “Step in any direction”, “Step or smaller leap in opposite direction”, or “Leap in opposite direction”.
  • Steps & Leaps: Move to the right to have your melody movement be more “scalar” or step-wise, and move to the left to add more leaps to the melody.
  • Note Repetition: Move to the right to increase the number of consecutive repeated notes in the melody.
  • Note Range: Default range is G2 to F4 (common tenor range).
  • Random Movement: Specify the probability of an 'expected' movement. When set to 100%: 7th will move up to the root, and 4th will move down to the third (and other rules). Please note that sometimes the 'expected' movement is not possible when other conditions do not allow it.


  • Set the Movement slider all the way to the right (100% expected), and increase the Note Repetition slider for more “melodic” results.
  • Set the Steps slider for a majority of steps (with fewer % leaps) for additional “melodic” results.
  • Set the Climax to “No Climax” for melodies that don’t reach a “peak.” (a lot of melodies don’t… they hang around in one place, unless the melody is deliberately trying to draw attention to itself (then, a climax is recommended).

To save pages and your time, we encourage you to experiment with the other Rhythm types for the Melody Generator. The Probabilistic Rhythm is one of the most useful rhythm types for melodies (we’ve done extensive tests to see which rhythm type should be the default, and the Probabilistic Rhythm always produced the most useful results, and quickly. Though ALL of the Rhythm types will generate something useful. Notice how (after selecting the other Rhythm types) that all of the parameters might be similar, with slight changes to accommodate the legato and/or monophonic performance of melody.

Modern Chord Pattern Generator

Create EDM chords with this phrase generator! For best results use 'Modern Rhythm' or 'Modern Random Rhythm' as the rhythm generator or you may edit the rhythm manually.

Modern Chord Pattern Generator Settings

  • Chord Placement: choose which rhythm notes represents the chord notes. 'Auto' will place a chord to each 8th note, 'All' means that all rhythm notes are chords
  • Chord Notes: specify which chord notes to use for the full chord. Available settings: Root, 3rd, 5th, 7th, 9th, Root-1 Octave, 3rd-1 Octave, 5th-1 Octave, 7th-1 Octave, 9th-1 Octave
  • Chord Polyphony: Decide to use one chord note at a time, or all chords notes
  • Chord Note Length: the length of chords notes. Available settings: As In Rhythm, Until Next Chord, Until Next Chord-16th Note, 16th Note
  • Bass Placement: choose which rhythm notes represents the bass notes. 'Auto' will place a bass note to each 16th note, 'All' means that bass notes are placed to all rhythm notes
  • Bass Note: Select which note to use as bass. Available settings: Random, Chord Root, 3rd, 5th
  • Bass Note Octave: Bass note transposition
  • Bass Note Length: the length of bass notes. Available settings: As In Rhythm, Until Next Bass, Until Next Bass-16th Note, 16th Note

Ostinato Generator

An ostinato is a recurring rhythmic or melodic pattern often found in both classical compositions and popular songs. Ostinato plays an important part in improvised music (rock and jazz), in which it is often referred to as a riff or a vamp. The Ostinato Generator does not use an external rhythm pattern.

Ostinato Generator Settings

  • Pattern: choose from many pattern presets
  • Division: used for making the rhythm, notes will start at 'division' positions. Available settings: 1/8, 1/8T, 1/16, 1/16T, 1/32, 1/32T, 1/64
  • Note Length: the note length for all notes (equal length). Available settings: Same as Division, 1/8, 1/8T, 1/16, 1/16T, 1/32, 1/32T, 1/64
  • Repeat Notes: it is possible to repeat notes maximum 4 times
  • Pattern Length (Retrigger): pattern length in quarter notes. The pattern is retriggered when this length is reached.
  • Insert Chord Root Note Every: insert chord root note one octave below every Nth event (not quarter note)
  • Changed Note Count: the number of notes that are changed randomly in 'pattern length' duration. Downbeats and the first 3 notes are never changed.
  • Possible Intervals: specify allowed up and down motion intervals, in scale steps. Available settings: +1 to +7, -1 to -7 scale steps

Percussion Generator

Create percussion patterns using multiple percussion instruments. Set the drum map first, use a percussion soundfont/VSTi instrument. You can re-generate one percussion, or all (unlocked) percussion instruments. Clicking on the pencil icon will open the rhythm generator options, where you can adjust the rhythm, or set up the rhythm manually.

Phrase Container

The Phrase Container lays out phrases in a certain order. Typically you add the phrases to be used in the list, of which the Phrase Container will select the specified number of phrases, that it will lay down using the specified arrangement.

Phrase Container Settings

  • Number Of Phrases: number of phrases to select randomly from the list
  • Arrangement: order of phrases. The available settings depend on 'number of phrases'.
  • Possible Phrases: add the phrases that you want to include in the container. When there are more phrases than the 'number of phrases' setting, the necessary number of phrases are randomly selected from the list

Phrase Morpher

Phrase Morphing means that when you place a 'source' and 'target' phrase in the composition, the phrases between the two will be composed automatically by RapidComposer so that there is a smooth transition from the source phrase to the target phrase. There are several options to control this transition. Usually there are many possible transitions, if you don't like the one offered by the program, pressing 'Regenerate' will create a different transition.

Phrase Morpher Settings

  • Quantization: Horizontal note movement control. Specify if you allow notes moving in time and if so how they are quantized. Notes moving in time will change the rhythm, so if that is not what you want it is best to disable this option. Available settings: Disable Note Movement In Time, 1/4, 1/8, 1/16, 1/32, 1/64, 1/128
  • Vertical Movement: Vertical note movement control. Specify if you allow notes moving vertically (becoming higher or lower notes) and if so how they are handled. Moving notes can be snapped to scale notes or semitones. Available settings: Disable Vertical Note Movement, Snap To Semitones, Snap To Scale
  • Pair Note Additions And Removals: When checked adding a target note and removing a source note will happen at the same time as far as other conditions allow. This results a smoother transition.
  • Handle Chord Notes Together: When checked chord notes with no offset will be added/removed together.
  • Apply Automatic Transposition: Specify if transposition is applied to the generated phrases. When checked the highest note of the source phrase will approximate the highest note of the target phrase. This setting is ignored when guitar chords are used.

Piano Chord Pattern Generator

The Piano Chord Pattern Generator makes separate patterns for the left and right hands. The left hand (bass) patterns are taken from presets which have their own rhythm. The right hand uses the rhythm generator output, and applies chord patterns on the rhythm.

Piano Run Generator

The Piano Run Generator offers a variable-note-length run through different octaves, in any direction, to easily add intensity or energy to a Composition. If you’re into minimalist piano composers such as Philip Glass or even Moby, you’ll love this Generator!

Piano Run Generator Settings

  • Technique: the “style” of the run. Available settings: Straddle, Straddle Without Middle Note, 2-1 Breakup, 3-1 Breakup, Waterfall, Waterfall Using Inversions
  • Motion: Upwards, Downward, Up-Down, Down-Up, Up-Down-Up-Down, Down-Up-Down-Up
  • Up Motion Range: the number of events (not quarter notes or semitones!) when moving up.
  • Down Motion Range: the number of events (not quarter notes or semitones!) when moving down.
  • Division: used for making the rhythm, notes will start at 'division' positions. Available settings: 1/8, 1/8T, 1/16, 1/16T, 1/32, 1/32T, 1/64
  • Note Length: the note length for all notes (equal length). Available settings: Same as Division, 1/8, 1/4, 1/2

Random Melody Generator

This is a much simpler melody generator than 'Melody Generator' with less options. But still, it can make very good melodies.

Random Melody Generator Settings

  • Options:
    • Wide Melody (Bigger Steps): allow bigger jumps for notes.
    • Last Note Is I: the last note becomes the root note of tonic
    • Force Chord Note For Notes Longer Than 2/4: longer notes will be chord notes when this option is checked
  • Harmony Note Probability: higher probability means more chord notes will be used in the melody
  • Note Range: melody notes will be generated in the note range. Default: G2-F4
  • Note Repetition Probability: higher probability means more notes repeated.


This is an empty phrase used only in the Phrase Container and Idea Tool to add rest between phrases.

Rhythm Mapper

You can convert any phrase to a 'Rhythm Mapper' which lets you use a different rhythm pattern for the phrase. This is available only in the 'Convert Phrase To Generator' menu in the Phrase Inspector.

Direct 1:1 Mapping

The rhythm events are mapped to phrase events. It is not the rhythm length that counts but the number of events in the rhythm. First the algorithm locates 'events' in the original phrase. An event has a position and a length. Events are when note(s) begin and last until the next note/event. Multiple notes (e.g. a chord) may belong to a single event. Also all rhythm notes are considered as an 'event'. Then the rhythm events are applied to the phrase, by shortening phrase notes if needed. Please note: a faster rhythm may change the phrase length. E.g. when you have 4 quarter notes, and you apply a rhythm consisting of eighth notes, the phrase becomes half the length. So the phrase length may change when using “Direct 1:1 Mapping”.

Preserve Phrase Shape

This functionality is the same as the Apply Rhythm variation. The phrase length does not change.

Strings Staccato Generator

The Staccato Strings Generator is obviously best utilized with a Staccato Strings soundfont or VSTi. This Generator is absolutely perfect to create classical runs/arpeggios, that stay true to string ensemble arrangements, and the intervals they often use. The algorithm was painstakingly created through extensive study of classical compositions by Beethoven, Mozart, and Bach.

If you love classical music and the beauty of staccato string arpeggios, this Generator might be the missing puzzle piece for your ideas.

Strings Staccato Generator Settings

  • Polyphony: How “thin” the Phrase can be (Polyphony 3), or how “full” (Polyphony 8 or 9). Put simply: Polyphony 3 means 3 performers playing complimentary arpeggios, and Polyphony 9 or 10 means more than 3 performers playing complimentary arpeggios in different octaves.
  • Density: Default setting is Low+Medium+High. Other available settings are Low, Low+Medium, Medium, Medium+High, and High.

Strum Pattern Generator

Create interesting and realistic guitar strum patterns with this generator! Use the 'Steel Guitar' preset from the included 'GeneralUser GS-RC' soundfont, or similar virtual instrument.

Let’s get to know Generators in detail. First, open up the Phrase Browser:

As you can see, there are several Generator types. Each phrase generator makes its own unique patterns, for different purposes you need to use different phrase generators. You can learn more about them in the next Section (Generator Parameters). In earlier chapters, we mentioned which Generators are more commonly used, and which ones are used less frequently. In case you forgot, here are the most common Generator types, according to our customers/users:

Bass, Chord, Fingerpicking, Generic, and Melody Generators. Let’s start a New Composition, and create a chord progression. Right-click the first chord on each bar (in the Chord Selector window, choose “Scale Degrees” instead of “List”, to work with the chords by Roman Numerals.). Now, create the common chord progression I - V - VIm - IV.

Now, let’s create several new tracks in our Composition, by pressing the + key on your keyboard three times (first click on a track to make it the keyboard focus). This should create 4 tracks total.

Now let’s set the instrument for each track that we’re going to put a Generator on. In these examples, we will be using the included Soundfonts that come with RapidComposer. To customize the Instrument for each track, you’ll need to pull up the Track Inspector. In case you forgot, we can access the Track Inspector by right-clicking the Track Header (where the name of each Track is).

Leave track 1’s Instrument as default (it defaults to the RCPiano soundfont). Set track 2’s Instrument to the “GeneralUser GS-RC” soundfont, Acoustic Bass preset (this will be our Bass track, of course) Set track 3’s Instrument to the “GeneralUser GS-RC” soundfont, Nylon Guitar preset (we will be putting a Fingerpicking Generator on this track). Set track 4’s Instrument to the “GeneralUser GS-RC” soundfont, Clarinet or any other lead preset (this will be our Melody Generator track). If you are using the LE version, you can skip adding a 4th track, as Melody Generator is only available in the Full version.

Your Composition should now have each track set to a different soundfont presets.

Now insert some chords…. for this example, our progression is I - V - VIm - IV (C - G - Am - F) and we left our Composition / Master Track settings default (key of C, 120BPM, 4/4 time).

Left-click the Track Header for Track 1, so Track 1 is the active/selected track. Hit Q on your computer keyboard, and Track 1 will fill with the default Generic Generator.

Left-click the Track Header for Track 2, so Track 2 is the active/selected track. Hit B on your computer keyboard, and Track 2 will fill with the default Bass Generator.

Left-click the Track Header for Track 3, so Track 3 is the active/selected track. Hit N on your computer keyboard, and Track 3 will fill with the default Fingerpicking Generator.

Left-click the Track Header for Track 4, so Track 4 is the active/selected track. Hit M on your computer keyboard, and Track 4 will fill with the default Melody Generator (not available in LE version).

Your Composition should now look like this:

We’re going to “tweak” one Generator at a time in this chapter. Let’s first work with the Generic Generator on Track 1. To pull up the Phrase Inspector window, right-click one of the Phrases (for example, the Phrase in Bar 1, which plays through the I chord).

You’ll see this Phrase Inspector window (at right). There are 5 icons at the top of the window. Click the 3rd one, which looks like a magic wand. This is where you will make the common changes to your Generators.

NOTE: For these examples, we won’t change much, but the next Section of this Chapter (Generator Parameters) shows the many, many ways Generators can be “tweaked” to achieve your desired result.

After you click the magic wand icon, you’ll see that the Phrase Inspector window enlarges and shows lots of cool parameters for the Generic Generator we placed on Track 1. Let’s hit the main PLAY button to hear how the Phrase sounds, with the rest of the tracks. Sounds alright, but we might want to tweak the Generic Generator by “randomizing” it (in RC, this is called “Generate+Apply” and there is also a keyboard shortcut for it, which is the letter G (after a Generator is selected).

With the Phrase highlighted and the Phrase Inspector window open, we can hit the letter G to create a new randomization of the Generator. Another easy and fast way to do this is as follows: Hit the right-facing arrow next to the Generator name. Whichever way you choose, you’ll see the 1/1 changed to 2/2.

This is called Phrase Local History. What it allows you to do is save and recall previous states of phrase generation (most commonly used with Generators). For example: “4th of 4”, or “6th of 6” near the Generator names. These indicate that we’ve generated/applied three additional Generators in one generator, or five additional Generators (using different parameters) in another. These can be recalled and changed at any time, by clicking the left or right arrows on each phrase!

Let’s go back to our Composition. Press PLAY again and listen to all four bars. Sounds pretty good, but maybe the Melody Generator in Bar 1 isn’t complimenting the Composition the way we’d hoped. Let’s work with Phrase Local History some more, but before we do, let’s tweak some of the Melody Generator parameters, in the Phrase that is located on the 1st bar.

1. Change the “Division” parameters to 1/4.

2. Change the “Mode” to Scale Notes+Chord Notes., instead of Downbeat is always a Chord Note.

3. Now, click the “Regenerate!” button. Then “Apply To Selection.” (or just hit the letter G, as it combines both commands).

4. Press PLAY. Still not satisfied?

5. Left-click the right-facing arrow next to the Generator name, to create entirely new Generator Phrases quickly (as long as the Generator is highlighted). Both the letter G and clicking the right-facing arrow do the same thing: “Generate+Apply”.

6. Keep pressing PLAY until you find something you like.

In the screenshot below, it took us only 4 additional generations/randomizations of the Melody Generator before we found something we liked. Initially we were going to go with the 1st generation. But we decided after listening back to the others, that the 5th generation sounded better to our ears. To cycle through the generations, simply left-click the left-facing arrow or right-facing arrow, and you can press PLAY to see how each sounds in the Composition. Truly rapid composing!