AM Posted June 14, 2017 Share Posted June 14, 2017 ;;; -------------------------------------------------------------------------- ;;; "mirror image" of a cutout ;;; -------------------------------------------------------------------------- ;;; this function is generating a "mirror image" of a cutout ;;; by random-length/pos or by event-numbers ;;; the "untaken" part will be replaced by rests ;;; the "special thing is" to connect it exactly/immediately to the original-seq ;;; and as filtered-seq you could use it in an other part/instrument ;;; i coded it for my current work... so, take it or delete it! (defun mirror-seq (n omn-list &key (type 'r)) (let ((single-seq (single-events omn-list)) (seq) (rests)) (progn (setf seq (flatten (loop repeat (if (listp n) (cadr n) (1+ (random (- (length single-seq) n)))) for i in single-seq collect i))) (setf rests (neg! (apply '+ (mapcar 'abs (omn :length (flatten seq)))))) (setf seq (cond ((equal type 'r) (gen-retrograde seq)) ((equal type 'i) (pitch-invert seq)) ((equal type 'ri) (pitch-invert (gen-retrograde seq))))) (setf seq (flatten (loop repeat (if (listp n) (- (cadr n) (car n)) n) for i in (single-events seq) collect i))) (flatten (list rests seq))))) ;;; examples ;;; if n = integer -> random-seq ;;; if n = integer-list -> event-posititon => constant ;;; types r / i / ri (setf seq '(e. b3 mf c4 s d4 pp q eb4 e4 f4 t fs4)) ;;; retro (setf exp1 (mirror-seq 2 seq :type 'r)) (setf exp2 (mirror-seq '(1 4) seq :type 'r)) ;;; retro/inv ;(setf exp1 (mirror-seq 2 seq :type 'ri)) ;(setf exp2 (mirror-seq '(1 4) seq :type 'ri)) ;;; inv ;(setf exp1 (mirror-seq 2 seq :type 'i)) ;(setf exp2 (mirror-seq '(1 4) seq :type 'i)) (def-score only-anonsense-example (:title "exp" :key-signature 'atonal :time-signature '(4 4) :tempo 124 :layout (bracket-group (treble-layout 'original) (treble-layout 'exp1) (bass-layout 'exp2))) (original :omn seq :channel 1 :port 1 :sound 'gm :program 'acoustic-grand-piano) (exp1 :omn (pitch-transpose 0 exp1) :channel 1 :port 1 :sound 'gm :program 'acoustic-grand-piano) (exp2 :omn (pitch-transpose 0 exp2) :channel 1 :port 1 :sound 'gm :program 'acoustic-grand-piano)) added 3 minutes later in comination with length-augmentation (and tranpositions) you could generate a "distorted mirror image" in an other part/instrument Quote Link to comment Share on other sites More sharing options...
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