Function to create random midi channel number

[PatrickMimran]

Hello , i am looking to find a way to assign random midi channel numbers with the possibility to set some repetition of midi channel number as an option EX : in turn midi channel 1 2 3 4 5 6   or   1 1 1 1 2 2 2 2 3 3 3 12 13 14  etc  .... The midi channel are distributed for each pitch, beat  or a measure or set of measures per voice

 

Thanks

 

Patrick

[erka]

I don't think it is possible  to change the midi-channel in the instrument this way.

But what you can do is influence what events from the omn-list gets played on the instrument channel.

There are probably better ways and this can be improved.

 

;; evaluate all
;; evaluate pattern you want to use
;; cmd-1 def-score
;; for external midi comment rk_evpos-gm and uncomment rk_evpos-extern

;; function for :omn in :instrument in def-score
(defun events-to-ch (ch poslist omnl)
(let* ( (somnl (single-events (flatten omnl)))
        (chplist (position-item ch poslist)))
  (loop for n from 0 to (length somnl)
        for i in somnl collect 
       (if ( equal n (car (member n chplist))) i
         (if (event-restp i) i (length-invert i))))
))


(setf mat
      '((5q c4 p cs5 pp d4 p ds5 pp e4 p)
        (s f5 pp fs4 mf g4 pp gs5 mf)
        (5q a4 p as5 mf b4 mp c4 pp cs5 d4 p ds5 mf e4 mp f5 pp fs4)
        (e g4 gs5 s a4 pp e as5 mf s b4 e c4 pp s cs5 mf e d4 -q)
        (s ds5 pp e4 p f5 mp fs4 pp 3q g4 p gs5 mp
           a4 pp q as5 p 5q b4 mp c4 pp cs5 p d4 mp ds5 pp)
        (s e4 p f5 pp fs4 p g4 pp)))

;;pattern-examples for the function events-to-ch called in :omn of instrument
;; the numbers e.g. '(1 2 3 4) are the midi-channels
(setf patt1 (gen-repeat 100 '(1 4)))
(setf patt1 (gen-repeat 100 (gi '(4 1..4 2 4..1))))
(setf patt1 (gen-repeat 100 '(2 4 3 2)))
(setf patt1 (gen-repeat 100 (rp '((1 1) (1 2) (1 3) (1 4))))) 
(setf patt1 (gen-repeat 100 (rp '((4 1) (3 2) (1 3) (2 4)))))
(setf patt1 (gen-repeat 100 (rp '((4 1) (4 2) (3 3) (1 12) (1 13) (1 14)))))
(setf patt1 (rnd-sample 500 '(1 2 3 4) :seed 300))
(setf patt1 (rnd-sample 500 '(1 2) :seed 300))
(setf patt1 (gen-repeat 100 '(1 2 3 4)))

(def-score rk_evpos-gm
           (:title "rk_evpos_gm"
            :key-signature 'chromatic
            :time-signature '(4 4)
            :tempo 120)

 (instrument1 
  :omn  (events-to-ch 1 patt1 mat)
  :channel 1
  :sound 'gm
  :program 'Lead-2-Sawtooth)

 (instrument2 
  :omn (events-to-ch 2 patt1 mat)
  :channel 2
  :sound 'gm
  :program 'Violin)

 (instrument3 
  :omn  (events-to-ch 3 patt1 mat)
  :channel 3
  :sound 'gm
  :program 'Trumpet)

 (instrument4 
  :omn (events-to-ch 4 patt1 mat)
  :channel 4
  :sound 'gm
  :program 'Marimba)
)
#|
(def-score rk_evpos-extern
           (:title "rk_evpos_extern"
            :key-signature 'chromatic
            :time-signature '(4 4)
            :tempo 120)

 (instrument1 
  :omn  (events-to-ch 1 patt1 mat)
  :port 0
  :channel 1)

 (instrument2 
  :omn (events-to-ch 2 patt1 mat)
  :port 0
  :channel 2)

 (instrument3 
  :omn  (events-to-ch 3 patt1 mat)
  :port 0
  :channel 3)

 (instrument4 
  :omn (events-to-ch 4 patt1 mat)
  :port 0
  :channel 4)
)
|#
(midi-destinations)

 

Edited August 11, 2023 by erka
code was not complete

[PatrickMimran]

Thank you

[erka]

I edited my first post as it was not complete. I had not inserted rests for the channels that were not playing.  Now it does what it should. If there are cases in the omn I have not considered please let me know.

If there are better ways to do this I would like to know.

Always learning.