Can You Transpose Each Staff Separately for MIDI Output in LilyPond?
Let's say you're working on a complex musical piece with multiple instruments and you need to transpose each instrument's part individually for MIDI output. You're using LilyPond, and you wonder: Is it possible to reference and transpose each staff separately for MIDI output only?
The short answer is yes, but with some limitations. LilyPond doesn't directly offer a simple "transpose each staff" command for MIDI. However, you can leverage its powerful scripting capabilities to achieve this result.
Here's a basic example of how you might approach this:
\version "2.22.0"
#(set-global-staff-size 18)
\score {
\new StaffGroup <<
\new Staff \relative c' {
c d e f g a b c'
}
\new Staff \relative c {
c' d' e' f' g' a' b' c''
}
>>
\midi {
\context StaffGroup <<
\override Staff.midiInstrument = #'violin
\override Staff.midiTranspose = 4
\override Staff.midiChannel = 1
\override Staff.midiProgram = 41
\new Staff <<
\relative c' {
c d e f g a b c'
}
>>
\override Staff.midiInstrument = #'flute
\override Staff.midiTranspose = 7
\override Staff.midiChannel = 2
\override Staff.midiProgram = 73
\new Staff <<
\relative c {
c' d' e' f' g' a' b' c''
}
>>
>>
}
}
Explanation:
\scoreand\midiblocks: This basic structure separates the visual score from the MIDI output.\new StaffGroup: Groups the two staves to be treated together for visual layout.\override Staff.midiInstrument = #'violin: This assigns the specified instrument (violin in this case) to the first staff for MIDI output.\override Staff.midiTranspose = 4: This transposes the first staff's notes up by 4 semitones in the MIDI output.\override Staff.midiChannel = 1: This assigns the first staff to MIDI channel 1.\override Staff.midiProgram = 41: This sets the MIDI program change for the first staff (41 corresponds to violin).- Repeat for each staff: The process is repeated for the second staff, specifying a different instrument, transpose value, channel, and MIDI program change.
Key Considerations:
- Transposing in the MIDI context: Remember that transposition in LilyPond's MIDI output only affects how the notes are sent to your MIDI device. The visual score remains unchanged.
- MIDI programs: Refer to MIDI program numbers to specify specific instrument sounds. There are various online resources available that list MIDI program numbers for different instruments.
- Scripting for complex scenarios: For more complex scenarios with multiple staves and specific transposition requirements, explore LilyPond's scripting capabilities using Scheme. This allows you to define custom functions and loops to automate the process for a large number of staves.
Resources:
- LilyPond Documentation: https://lilypond.org/doc/v2.22/Documentation/notation/midi
- MIDI program numbers: https://www.midi.org/specifications/item/gm-level-1-sound-set
By understanding the core concepts and exploring the possibilities, you can effectively manipulate MIDI output in LilyPond to achieve your desired results, even when it comes to transposing each staff separately.
