Here is the score of a short piano study using Harmony from a row, and user defined functions encapsulated in other functions for the score generation.

Provided here as an example of a possible usage of functions defined by the user specifically for a given score.

(defun arp1 (nb &key (rev nil) (rnge '(c1 c7))
                (nbitv 5) (len (gen-repeat 16 '(s))) 
                (vel '(mf))(art '(leg))
                (itvlist '(1 2 4 5 1 3 -1 -2)))
  (make-omn
   :pitch (ambitus rnge
                   (if rev
                     (gen-retrograde
                      (integer-to-pitch
                       (gen-integer-step 
                        -24 
                        nb
                        (rnd-sample nbitv itvlist))))
                     (integer-to-pitch
                      (gen-integer-step 
                       -24 
                       nb
                       (rnd-sample nbitv itvlist)))))
   :length (length-trim nb len)
   :velocity vel
   :articulation art))

(defun chrd1 (nb &key (ofst 3) (rnge '(c1 c7)) 
                 (chsize 4) (trspt 0)(rnd-oct nil)
                 (len (gen-repeat 4 '(q))) 
                 (vel '(mf))(art '(leg)))
  (make-omn
   :pitch (ambitus 
           rnge 
           (gen-chord2 
            nb
            chsize 
            (rnd-row :type :pitch)
            :offset ofst
            :transpose trspt
            :rnd-octaves rnd-oct))        
   :length (length-trim nb len)
   :velocity vel
   :articulation art))

(defparameter size 64)
(setf row (rnd-row :type :pitch))
(setf hchords (gen-chord2 size 5 row
                          :offset (rnd-sample size (gen-integer 4))
                          :transpose (rnd-sample size (gen-integer -12 12))))

(setf path (tonality-series hchords))
(setf study
      (tonality-map
       path
       (gen-loop size
                 (eval
                  (car
                   (rnd-sample
                    1
                    '((length-fix
                       (arp1 (car (rnd-number 1 6 12))
                             :rnge (rnd-pick '((c1 c7)(c5 c7)(c1 c3)(c3 c6)(g5 g6)(e2 g5)))
                             :nbitv (rnd-pick '(1 2 3 4 5 6 7 8))
                             :vel (rnd-pick '((pp)(p)(mp)(mf)(f)(ff)))
                             :art (rnd-pick '((stacc)(leg)(marc)(stacs)(mart)))
                             :len (rnd-pick `(,(rnd-sample 12 '(1/24 1/8 1/8 1/16 1/16 1/32 -1/8 -1/8))
                                              ,(gen-repeat 16 '(s))
                                              ,(gen-repeat 12 '(1/12))
                                              ,(rnd-sample 8 '(e e s s s -e))
                                              ,(rnd-sample 8 '(e e s s s -q s s s -e))))
                             :itvlist (rnd-pick '((8 6 14 -8 -6)
                                                  (1 2 -1 2)
                                                  (1 2 3 4 -1 -2 -3 -4)
                                                  (2 4 6 -1 -3 -7)))))
                      (length-fix
                       (chrd1 (car (rnd-number 1 1 8))
                              :ofst (rnd-pick '(1 2 3 4))
                              :rnge (rnd-pick '((c1 c7)(c5 c7)(c1 c3)(c3 c6)(g5 g6)(e2 g5)))
                              :chsize (rnd-pick '(2 3 4 5 6))
                              :rnd-oct t
                              :len (rnd-pick `(,(rnd-sample 4 '(h -q q))
                                               ,(gen-repeat 8 '(e))
                                               ,(gen-repeat 5 '(1/12))
                                               ,(gen-repeat 4 '(e. s))
                                               ,(rnd-sample 8 '(h q -q q q))
                                               ,(rnd-sample 8 '(e e e e q -e))))
                              :vel (rnd-pick '((pp)(p)(mp)(mf)(f)(ff)))
                              :art (rnd-pick '((stacc)(leg)(marc)(stacs)(mart))))))))))))

(def-score study
           (:composer "S.Boussuge"
                      :copyright "Copyright © 2015 S.Boussuge"
                      :key-signature atonal
                      :time-signature (get-time-signature study)
                      :tempo 118
                      :layout (piano-grand-layout 'piano))
  
  (piano
   :omn study
   :channel 1
   :sound 'gm
   :program 'acoustic-grand-piano
   :port 0))

 

 

S.B.

Impressive !