Lume has a standard for MIDI files to ensure some cross compatibility between different layouts, known as the Lume MIDI Standard. It is used specifically by complex layouts (multi-channel MIDI files). Simple layouts ignore MIDI channels and will accept all notes.

Note Value

Lume accepts note values in the range of [12, 119] (C0 to B8, inclusive), giving a range of 9 octaves.

The note values within [0, 11] (C-1 to B-1, inclusive) and [120, 127] (C9 to G9, inclusive) are reserved for graphics to use as control values. They should not be used for normal rendering.

Channels

Lume assigns each channel an instrument type that it looks out for. The list

The current Lume standard for MIDI channels is as follows:

Channel	Type
01	Piano/Keyboard
02	Lead 1 (Primary)
03	Lead 2 (Secondary)
04	[unused]
05	[unused]
06	[unused]
07	[unused]
08	[unused]
09	[unused]
10	Drums
11	Pitched Percussion
12	[unused]
13	[unused]
14	Bass
15	[unused]
16	[unused]

The subsections go into more detail on the expectation of each channel.

Channel 1 (Piano/Keyboard)

Channel 1 is a general-purpose channel for any pitched instrument, capable of being used by monophonic and polyphonic parts. However, because it is intended to be versatile (handle a lot of notes at once), it's recommended to use this channel for chords mainly, such as piano and string parts.

Channel 10

To help Lume have some compatibility with files that comply with general MIDI, channel 10 is designated as the drums channel.

However,

Lume's channel 10 configuration is based off of General MIDI's system, which specifically locks channel 10 to percussive sounds, with a percussive map that denotes the sound that each MIDI key represents.

Lume uses a smaller map, only including 16 notes rather than full 47. This is because Lume's visualizers are often abstract than not, and do not require a sound to be mapped to a specific key.

The full list of Lume's percussion map is listed below (sorted from top-left to bottom-right):

Name	MIDI	Note
Crash 1	49	C#3
Crash 2	57	A3
Ride	51	D#3
Ride Bell	53	F3
High Tom	50	D3
Mid Tom	48	C3
Low Tom	45	A2
Floor Tom	43	G2
Snare 1	38	D2
Snare 2	40	E2
Open Hi-Hat	46	A#2
Pedal Hi-Hat	44	G#2
Side Stick	37	C#2
Kick	36	C2
Closed Hi-Hat	42	F#2
Clap	39	D#2

The selection of notes is derived from the plugin Micro Drum Sampler (MDS), a built-in plugin from the DAW Waveform:

Note Precedence

Because different drum visualizers will support different amounts of notes, a note hierarchy exists to determine what notes take priority for rendering. This allows for full-size drum parts that use all 16 notes to be rendered with visualizers in a way that ensures that the most important notes are still shown.

For example, the Kick (36, C2) will always be included in a drum visualizer, as it has the highest predence out of all the notes.

The list of Lume's percussive map (sorted by highest to lowest precedence) is listed as such:

Name	MIDI	Note
Kick	36	C2
Snare 2	40	E2
Closed Hi-Hat	42	F#2
Open Hi-Hat	46	A#2
Pedal Hi-Hat	44	G#2
Clap	39	D#2
Side Stick	37	C#2
Snare 1	38	D2
High Tom	50	D3
Low Tom	45	A2
Crash 1	49	C#3
Ride	51	D#3
Crash 2	57	A3
Mid Tom	48	C3
Floor Tom	43	G2
Ride Bell	53	F3

A layout's documentation will include the amount of notes they support for drum parts.

Grid Layout

Visualizers that use a grid of buttons must have a button layout based off of MDS, specifically the first page.

This rule is excempt for grids of buttons represented pitched sounds, or grids larger than 4 by 4.

Grids smaller than 4 by 4 must adhere to a specific subsection of the grid, based off of the "importance" of the notes in the grid. A list of the officially-supported subsections are noted below:

Full Size Drum Grid (4 by 4)

2 by 4

2 by 2

Non-Grid Layouts

Non-grid drum visualizers do not need to base their drum positionings based off of the grid layouts (because they cannot), and simply need to adhere to the note precedence.

Velocity

Velocity is not processed by Lume.