Overview:

Genny is a generative MIDI sequencer using a Neotrellis M4. Patterns of up to 8 bars, each containing up to 16 beats can be programmed for up to 16 midi channels. There are then some features to randomise the playback to create some generative music.

Uploading the firmware:

There are many different ways to upload the firmware. I will explain doing it with Arduino or VS Code.

Arduino: Create a project called Genny and copy the .cpp and .h files into the project folder. Rename main.cpp to Genny.ino (replacing the file that already exists). Use the Board Manager to add Adafruit SAMD Boards and the Library Manager to add the Adafruit NeoTrellis M4 library. Press the upload button within the Arduino IDE.

VS Code: Get the Platform IO extension. Create a project for the neotrellis m4 board and copy the .cpp and .h files into the src folder. Press the upload button within the IDE.

Representing numbers:

Numbers are represented in binary format. When the button is on, it represents a 1 and when it is off it represents a 0. Multiple buttons are grouped together to represent the whole number, and to show this grouping the buttons are the same colour when turned on.

Of course if all the buttons are turned off, it represents a 0. However, for some parameters it does not make sense to have a 0, so instead Genny is adding 1 to the number. So instead of counting from $0$ to $2^{n-1}$, it counts from $1$ to $2^n$.

Making Music:

The 1st, 7th and 8th columns permanently have the same function, while the rest of the buttons' functions vary depending on the selected page.

beat3						instr3	play
beat2						instri2	nextBeat
beat1						instr1	nextBar
beat0						instr0	page

[beat] permanently represents the current beat number as a 4 bit binary number. Since it is a 4 bit binary number it counts from 0 to 15, instead of 1 to 16 (as would usually be done in music).

[instr] permanently represents which midi channel is selected as a 4 bit binary number.

[play] permanently functions as the play/stop button. The colour represents the current state. Green means it is playing, red means it stopped.

Pressing [nextBeat] causes an immediate jump to the next beat, while pressing [nextBar] causes an immediate jump to the next bar. The colour of these buttons represents the bar number.

[page] selects the page to display. The page number is represented by the colour and as the button is pressed a letter is displayed to indicate the current page. The function of each page is described below.

Show All (A):

In this page, all the melodies are simultaneously displayed. The colours of each instrument are summed together (as RGB), so if a blue instrument and a red instrument plays the same note at the same time, the button is purple.

One can also play an instrument by pressing the buttons. The channel that is being played is selected by the 7th column.

If black keys are included for the current channel(default), the tuning is as follows. The lowest note is an A on the bottom left, and then it chromatically increases to the right. The next row up is a 4th higher, just like many string instruments (such as guitar).

	C	C#	D	D#	E
	G	G#	A	A#	B
	D	D#	E	F	F#
	A	A#	B	C	C#

If black keys are excluded for the current channel, the tuning is as follows. Again the lowest note is an A on the bottom left.

	B	C	D	E	F
	D	E	F	G	A
	F	G	A	B	C
	A	B	C	D	E

Edit Time (t):

	globalNumBeats3	clockMode	tap/1	localNumBeats3	runFree
	globalNumBeats2	globalTimeDeviance2	tap/2	localNumBeats2	localTimeDeviance2
	globalNumBeats1	globalTimeDeviance1	tap/3	localNumBeats1	localTimeDeviance1
	globalNumBeats0	globalTimeDeviance0	tap/4	localNumBeats0	localTimeDeviance0

[globalNumBeats] sets the amount of beats per bar. [localNumBeats] sets the amount of beats for only the current instrument and is useful for creating polyrhythms. If [runFree] is disabled and [localNumBeats] is less than [globalNumBeats], the current instrument repeats a pattern of length [localNumBeats] until the end of each bar. If [runFree] is enabled, the current instrument runs detached from the rest of the system, and the length of its bars is determined by [localNumBeats].

[clockMode] sets the midi clock mode in case you want to sync Genny with other midi devices. The colours indicate the mode as follows:

• Red: No synchronization
• Green: Genny is the master, so it determines the tempo
• Yellow: Genny is the slave, so it listens to the tempo from another device

With [globalTimeDeviance], you can make the time between beats deviate from perfect timing. With [localTimeDeviance], you can make the current instrument deviate from the beat. It is recommended to add local deviance to any instrument that plays chords, because then the individual notes in the chord aren't played exactly simultaneously and this gives a much more natural sound.

The tap buttons are for tap tempo. The beat length is determined by the time between pressing and releasing one of the buttons. With [tap/1] you directly tap the tempo. With [tap/2] the tempo is double what you tap. With [tap/3] the tempo is 3 times what you tap. With [tap/4] the tempo is 4 times what you tap.

Record (R):

This page is used to record melodies. Pressing a button puts a midi NoteOn command on the current beat, and releasing a button puts a midi NoteOff command on the current beat. You can either record a melody in realtime while the system is playing,or you could manually input a melody by navigating to the time point(beat and bar) you want to edit and then pressing or releasing the button corresponding to the note you want. The tuning is the same as described for the Show All section.

Edit Bars (b):

	randomBar	applyToAll	lock	bar0	bar1
	numBar2	groupSize2	repeats2	bar2	bar3
	numBar1	groupSize1	repeats1	bar4	bar5
	numBar0	groupSize0	repeats0	bar6	bar7

[bar] is used to set the bar repetition structure. The colour of each button sets which bar to play, and the location sets when to play it. For example, if every button is red, the current instrument would continuously play the first bar. This is useful for having a repetitive drumbeat without having to manually program it for all 8 bars.

The bars are represented by the colours in the table below. Note that on some screens some colours might not be visually seperable, but on Genny they are. It starts with red, then fades through shades of orange,yellow and ends on green.

Bar 1	Bar 2	Bar 3	Bar 4	Bar 5	Bar 6	Bar 7	Bar 8

Changing the progression of bars is kind of counter intuitive, but once you get it you can put in patterns very fast. First press and hold the button that represents the bar number you want to set the other buttons to. Then press all the buttons you want to set to that bar number while still holding down the first button.

If [randomBar] is enabled, a new bar is selected at random at the end of each bar or group of bars.

You can change the total number of bars with [numBar]. The default is 8, which is the maximum.

If you want each bar to play multiple times before moving on to the next bar, you can set the number of repeats with [repeats]. You can group multiple bars together with [groupSize] to have, for example, 4 bars repeating 3 times before moving on to the next 4 bars. If [numBar] is not divisible by [groupSize], you can get long complicated progressions.

If [applyToAll] is on, then whatever changes you make to the bar progression is also applied on all the other channels, except those for which [lock] is engaged.

Other (O)

	velMin3	velMax3	velMode	blackKeys	prob1
	velMin2	velMax2	velParam2	octave2	prob0
	velMin1	velMax1	velParam1	octave1	randomNote
	velMin0	velMax0	velParam0	octave0	midiPanic

[velMax] sets the maximum velocity and the [velMin] sets the minimum velocity. [velMode] sets how the velocity varies, and [velParam] adjusts different parameters depending the velocity mode. There are 5 modes:

• Random uniform (blue): Each note's velocity is sampled from a random uniform distribution between the minimum and maximum velocities.

• Random walk (cyan): Each note's velocity is slightly bigger or smaller than that of the previous note. [velParam] sets the size of the steps.

• Accent strong beats (green): Strong beats are played at the max velocity, while the rest are played at the min velocity. [velParam] sets the number of weak beats between each strong beat.

• Ascending (Yellow): The first note of each bar is played at the minimum velocity, and linearly increases so that the last note is played at the maximum velocity.

• Descending (Red): The first note of each bar is played at the maximum velocity, and linearly decreases so that the last note is played at the minimum velocity.

[blackKeys] sets whether black keys are included or not. When they are included you can make more emotionally complex sounds, but when they are excluded you are guaranteed that every note is in CMaj/Amin. It is enabled by default.

[octave] sets the octave of the notes.

[prob] sets the probability of a note being played. When both buttons are on each note plays 100% of the time, and when both are off it is 0% and the current channel is essentially switched off. It sounds cool to have it in-between, so only some, but not all, notes play.

If [randomNote] is enabled, instead of playing the beats in sequence, a random beat within the bar is chosen every time. This allows generative melodies.

[midiPanic] sends the midi panic command. If a note is stuck, send this command to stop it.

Presets (P):

	root	roots	copySource3	mono	minorBlues
	chord	chords	copySource3	pop	majorBlues
	arpeggios	copyNotes	copySource3	copyBars	Co5
	clearNotes	randomNotes	copySource3	randomBars	ascending

This page is used to quickly write presets to the current channel so you don't have to manually input it every time. The 5th and 6th columns are used to set the bar repetition structure, and the 2nd and 3rd columns are used to set the notes within the bars. Take note, most of these buttons will overwrite whatever is currently written into the selected instrument.

It is assumed that the bars are associated with the following chords:

Bar 1	Bar 2	Bar 3	Bar 4	Bar 5	Bar 6	Bar 7	Bar 8
Am	B	C	Dm	Em	F	G	Am

The bar presets are as follows:

• [mono] puts the bars in the following order: 1, 1, 1, 1, 1, 1, 1, 1. This is useful for something such as a drum beat that repeats for every bar.
• [pop] puts the bars in the following order: 3, 7, 1, 6, 3, 7, 1, 6. These 4 chords are often used in pop songs.
• [minorBlues] puts the bars in the following order: 1, 1, 4, 1, 5, 4, 1, 1. This is an 8 bar version of the 12 bar blues.
• [majorBlues] puts the bars in the following order: 3, 3, 6, 3, 7, 6, 3, 3. This is the relative major of the minor blues.
• [Co5] puts the bars in the following order: 1, 4, 7, 3, 6, 2, 5, 8. This follows the circle of 5ths, and is also the progression used in Autumn Leaves.
• [randomBars] generates a random chord progression.
• [copyBars] copies into the selected instrument(7th column) the bar repetition structure of the instrument indicated by [copySource] (6th column).
• [ascending] puts the bars in the following order: 1, 2, 3, 4, 5, 6, 7, 8. This is the default order.

The note presets are as follows:

• [root] overwrites the first beat of each bar with just the root note corresponding to that bar.
• [roots] overwrites every beat with the root note of the corresponding bar.
• [chord] overwrites the first beat of each bar with the chord corresponding to that bar.
• [chords] overwrites every beat with the chord of the corresponding bar.
• [arpeggios] same as [chords], except the notes are arpeggiated.
• [randomNotes] places a random note on each beat.
• [clearNotes] deletes all the notes in the current instrument.
• [copyNotes] overwrites all the notes in the selected instrument(7th column) with the notes from the instrument indicated by [copySource] (6th column).