mull

Mozaic Updater for Linnstrument Lights

What is it?

A tool to allow MIDI files to control Linnstrument lights

What does it do?

mull updates the Linnstrument lights to show both notes in the current scale & chord, as well as in the immediate next scale & chord. The intention is to help in improvising on the Linnstrument by using color codes to show which notes are "playable" at any point, with the colors showing the role each note plays in the tune at that point.

To use it, create a MIDI file/stream containing the chords for the entire tune, and send it to the Linnstrument 1(?) beat ahead of the music being played.

How does it work

mull works like this:

Initial setup

• create a list of where every C, C#/Db, D, D#/Eb, E, F, F#/Gb, G ... note is on the Linnstrument
• create a list of color codes that can be sent to the Linnstrument
• maintain a map of which notes are currently set to which color

When a user initially selects a root note & scale:

• mull sets every root note to a certain color (e.g. blue)
• mull sets every note in the scale to a certain color (e.g. white)

When a new chord is sent to mull via MIDI, it changes the Linnstrument lights as follows:

NOTES IN SCALE	Note in next chord	Note not in next chord
Note in current chord	PURPLE	BLUE
Note not in current chord	YELLOW	BLUE if root, else WHITE

NOTES NOT IN SCALE	Note in next chord	Note not in next chord
Note in current chord	ORANGE	BLACK
Note not in current chord	ORANGE	BLACK

To update colors on the Linnstrument's pads

Setting the color of each pad requires 3 distinct MIDI CC messages to be sent to the Linnstrument

• set MIDI CC 20 to the column (0-15 or 0-24, depending on the model of Linnstrument)
• set MIDI CC 21 to the row (0-7)
• set MIDI CC 22 to the color
  • 0 to revert to the color configured in Linnstrument settings
  • 1 to display RED
  • 2 to display YELLOW
  • 3 to display GREEN
  • 4 to display CYAN
  • 5 to display BLUE
  • 6 to display MAGENTA
  • 7 to display BLACK (off)
  • 8 to display WHITE
  • 9 to display ORANGE
  • 10 to display LIME
  • 11 to display PINK

Note that the values of MIDI CC 20 & 21 are both persistent, so it's possible to e.g. work along a row of lights by setting CC 21 once, then setting CC 20 & 22 for each light in the row.

To map the allocation of MIDI notes assigned to each pad on the Linnstrument

Sending the following sequence of CC messages will return the MIDI note assigned to the bottom left pad:

• CC 98=43
• CC 99=2
• CC 38=7
• CC 6=2

To get the leftmost pad one row up from that, simply increment the CC 38 value by one:

• CC 98=43
• CC 99=2
• CC 38=8
• CC 6=2

This can be continued up to the top left pad:

• CC 98=43
• CC 99=2
• CC 38=14
• CC 6=2

Next, check the "handedness" of the Linnstrument as follows

• CC 98=43
• CC 99=2
• CC 38=90
• CC 6=1

This will determine if pads go up or down in value as you move to the right

Each will return a set of 6 CCs:

• CC 101 (ignore)
• CC 100 (ignore)
• CC 99 (ignore)
• CC 98 (row ID, encoded)
  • subtract 7 from this value to convert it to a 0-based row ID
• CC 6 (ignore)
• CC 38 (MIDI note for leftmost pad)

From this information, plus knowing whether the pads increase or decrease as you move to the right, it should be possible to calculate the MIDI note linked to each pad