[CM] time sig and instrument assignment

[taube at uiuc.edu]

>is there are way to alter, measure by measure, the time signature of a 
>midi file being output from (events)?
>
>is there any way to execute a program change on a given channel in the 
>same midi file?


Hi, the easiest way is to define functions that make time sigs and program change events and then call them in a score. In this example I use a seq but you could output via a a process just as easily.


? (define (tsig time num1 num2)
    (multiple-value-bind (m d)
        (make-time-signature num1 num2)
      (new midimsg :time time :msg m :data d)))

? (define (pchange time chan ins)
    (new midimsg :time time
         :msg (make-program-change chan ins)))

? (new seq :name 'test
       :subobjects
       (list
        (tsig 0 4 4)
        (pchange 0 0 0)
        (new midi :time 0 :duration 4 :keynum 60)
        (tsig 4 3 4)
        (pchange 4 1 2)
        (new midi :time 4 :duration 3 :channel 1)))
#<seq "test">

? (events #&test "test.mid")
"test.mid"

? (midi-file-print "test.mid")
File: test.mid 
Format: 0
Tracks: 1
Division: 480
Track 0, length 51
       0 #<Tempo Change 1000 ms>
       0 #<Time Signature 4/4 (24 clocks, 8 32nds)>
       0 #<Program-Change 0 "Acoustic-Grand-Piano">
       0 #<Note-On 0 60 64>
    1920 #<Note-Off 0 60 127>
       0 #<Time Signature 3/4 (24 clocks, 8 32nds)>
       0 #<Program-Change 1 "Electric-Grand-Piano">
       0 #<Note-On 1 60 64>
    1440 #<Note-Off 1 60 127>
"test.mid"
[16]>