Does anybody has an idea how I can achieve a readable (reasonable) output in which the lengths are quantized to quarters of a 4/4 measure. At the moment I get also 10-tuplets over 1/2 and even a 15-tuplet over 3/4.

Thanks for help, Achim

(setf lengths
      (flatten
       (loop with seed = (init-seed 123)
             ;; random number of quarters
             with quarterlist = (rnd-sum-to-size
                                 96 28
                                 '(2 3 4 5 6 7 8))
             ;; tuplet denominator for 1/4
             with division = 5
             ;; tuplet denominator per 4/4 measure
             with tup = (* division 4)
             for quarters in quarterlist
             ;; random number (numerator for rest)
             for rand = (rndn 1 1 (1- division))
             ;; rest (part of a tuplet)
             for rest = (/ rand tup)
             ;; overall duration - rest
             for dur = (- (/ (* division quarters) tup) rest)
             collect (quantize (list (* -1 rest) dur)
                               '(1 2 4 5) :type :ratio))))

quantize

?

(progn
  (init-seed 123)
  (setf quarterlist
        (rnd-sum-to-size 96 28 '(2 3 4 5 6 7 8)))
  (setf division 5)
  (setf tup (* division 4))
  (setf quarters quarterlist)
  (setf lengths (gen-loop
                 28
                 (progn
                   (setf rand (rndn 1 1 (1- division)))
                   (setf rest (/ rand tup))
                   (setf qs (car (setf quarters (gen-rotate 1 quarters))))
                   (setf dur (- (/ (* division qs) tup) rest))
                   (list (* -1 rest) dur))))

  (quantize
   (omn-to-time-signature
    (make-omn :length lengths
              :pitch '(c4))
    '(4 4))
   '(1 2 4 5)))