this is a unique symbol identifying the percussion
instrument. it is used as a lookup value so that it may easily be
specified in instr structures.
perc-staff
this is an integer of 1 or greater specifying on
which staff the instrument appears on.
perc-voice
this is an integer of 1 or greater specifying a
voice that this instrument belongs to. specifying different voices
prevents notes belonging to different instruments from being beamed
together.
perc-note
this is an integer or symbol designating where the
instrument's notes are to appear on the staff. the value is
interpreted with middle c in the center as if notated with an alto
clef signature. see event-note in the note class for information
on specifying notes with symbols. percussion notes should not require
flats or sharps.
perc-autodur
if set to t, indicates that fomus should determine
durations for this instrument. this is appropriate for percussion
instruments that don't have long sustain times and can therefore be
notated with durations that are simpler to read. notes containing
certain marks such as trills and tremolos are left unchanged. this
slot is t by default.
perc-marks
contains a list of to be added
to note objects that specify this percussion instrument. an example
value to put here might be ((:text "r.s." :up)) for a "rim shot"
percussion instrument.
perc-midinote-im
represents the midi note or notes used to import
midi data. this can either be an integer from 0 to 127 or a list
of such integers.
perc-midinote-ex
an integer value from 0 to 127 representing
the midi note used when exporting midi data.