Artificial Music

Posted On Thu, 08 Sep 2005 05:54:00 +0000. Filed in music. By Vaibhav Bhandari.

My rendition of Alap in Raag Bhup with Teen-taal in beats, the code is in lisp:

(setq BHUP-SCALE ‘(55 57 59 60 62 64 65 67 69 71 72 73 75 76)) (setq TEEN-TAAL-THEKA ‘((0 45 500 10 127) (500 41 500 10 127) (1000 41 500 10 127)(1500 45 500 10 127)))

(defun compose (number-of-events ontime) “(compose 77 0)” (if (zerop number-of-events)() (cons (list ontime (+ (choose-bhup-notes 0) 0) ;;to put it in MIDI range 1000 1 127) (compose (- number-of-events 1) (+ ontime 1000)))))

(defun surleena (number-of-events) “Alap with zor n zhala optimum @ 25 events” (let ((alap (long-notes (compose number-of-events 0) 0)) (zor-zhala (scale-tempo 0.5 (compose number-of-events 0))) (zor-theka (scale-tempo 1 (repeat-events 8 2000 TEEN-TAAL-THEKA)))) (append alap (shift-ontime (* 1000 number-of-events) zor-zhala) (shift-ontime (* 500 number-of-events) zor-theka) )) )

(defun long-notes (events change-so-far) “Assuming events are well-formed” (if (null events) () (let ((change (random 500))) (cons (change-tempo (first events) change-so-far change) (long-notes (rest events) (+ change change-so-far))))))

(defun change-tempo (event val tempo) “(change-tempo ‘(0 34 1000 1 127) 0 500) returns ‘(0 34 1500 1 127)” (list (+ (nth 0 event) val) (nth 1 event) (+ (nth 2 event) tempo) (nth 3 event) (nth 4 event) ) )

(defun choose-bhup-notes (number) “Picks one note from a flute based bhup scale” (let ((val (+ (random 23) 53))) (cond ((memberp val BHUP-SCALE) val) (t (choose-bhup-notes number)) )) )

(defun memberp (elem elist) “Is elem a member of elist” (cond ((= elem (first elist)) t) ((null (rest elist)) ()) ((not (null elist)) (memberp elem (rest elist)) ) ) )

(defun scale-tempo (factor events) “Scales tempo 0-1 1 implies no effect” (if (null events) () (let* ((event (first events)) (ontime (round (* factor (first event)))) (duration (round (* factor (third event))))) (cons (list ontime (second event) duration (fourth event) (fifth event)) (scale-tempo factor (rest events)) ))) )

Enjoy the code is LGPL.


Related posts you may enjoy: