make-rhythm   scheme

(define make-rhythm
   (lambda (beats tactus syncopation rhythm-list)
      (define beats-divisible-by-rlst
   (lambda (dur)
      (member 0 (map (lambda (r) (modulo dur r)) rhythm-list))))
      (set! rhythm-list (cl:sort rhythm-list >))
      (if (not (= 0 (modulo beats tactus)))
    (begin (log-error "Tactus must be a subdivision of beats") '())
    (if #f ;(not (beats-divisible-by-rlst beats))
        (begin (println "Impossible rhythm-list selection") '())
        (let loop ((rl '())
       (cnt 0))
     (if (null? rl) (list (random rhythm-list)))
     (let ((sum (apply + rl)))
        (cond ((> cnt 500)
         (log-error "Could not make valid rhythm")
         '())
        ((> sum beats)
         (loop (cdr rl) (+ cnt 1)))
        ((not (beats-divisible-by-rlst (- beats sum)))
         (loop (cdr rl) (+ cnt 1)))
        ((>= (car rhythm-list) (- beats sum))
         (cond ((= sum beats)
          (reverse rl))
         ((member (- beats sum) rhythm-list)
          (reverse (cons (car (member (- beats sum) rhythm-list)) rl)))
         (else (loop (cons (random rhythm-list) rl) (+ cnt 1)))))
        (else (if (= 0 (modulo sum tactus))
            (loop (cons (random rhythm-list) rl) (+ cnt 1))
            (if (> (random) (+ .05 syncopation))
          (loop (cons (car rl) rl) (+ cnt 1))
          (loop (cons (random rhythm-list) rl) (+ cnt 1))))))))))))