Posted November 28, 20186 yr ;;; THIS FUNCTION DOING SYMM TRANSPOSITIONS TO CONRACT (OR EXPAND, depends on INTERVAL) A CHORD or PITCH-SEQ ;;; default setting: it changes in every generation the highest and lowest pitch by an OCTAVE ;;; by changing :position (see examples) you could change which position should be changed/transposed ;;; default interval is 12 ;;; FUNCTION (defun chord-contraction/expansion (n pitchlist &key (position nil) (interval 12) (chord nil)) (let* ((pitchlist (if (chordp (car pitchlist)) (melodize pitchlist) pitchlist)) (position (if (null position) (list 0 (1- (length pitchlist))) (if (listp position) position (list position (- (1- (length pitchlist)) position))))) (pitchlist (cons pitchlist (loop repeat n collect (setf pitchlist (sort-asc (flatten (position-replace position (list (pitch-transpose interval (list (nth (car position) pitchlist))) (pitch-transpose (neg! interval) (list (nth (cadr position) pitchlist)))) pitchlist)))))))) (if (null chord) pitchlist (chordize pitchlist)))) ;;; EXAMPLES: evaluate by cmd3 (setf 12-tone-field '(f3 fs3 gs3 c4 d4 e4 b4 cs5 eb5 g5 a5 bb5)) (chord-contraction/expansion 4 12-tone-field :chord t) => ((f3fs3gs3c4d4e4b4cs5eb5g5a5bb5) (fs3gs3c4d4e4f4bb4b4cs5eb5g5a5) (gs3c4d4e4f4fs4a4bb4b4cs5eb5g5) (c4d4e4f4fs4g4gs4a4bb4b4cs5eb5) (d4eb4e4f4fs4g4gs4a4bb4b4c5cs5)) (chord-contraction/expansion 4 12-tone-field :chord t :interval 48) => ((f3fs3gs3c4d4e4b4cs5eb5g5a5bb5) (bb1fs3gs3c4d4e4b4cs5eb5g5a5f7) (f3fs3gs3c4d4e4b4cs5eb5g5a5bb5) (bb1fs3gs3c4d4e4b4cs5eb5g5a5f7) (f3fs3gs3c4d4e4b4cs5eb5g5a5bb5)) ;;; with spezific positions (inner change) (chord-contraction/expansion 4 12-tone-field :chord t :position 3) => ((f3fs3gs3c4d4e4b4cs5eb5g5a5bb5) (f3fs3gs3d4eb4e4b4c5cs5g5a5bb5) (f3fs3gs3cs4eb4e4b4c5d5g5a5bb5) (f3fs3gs3d4eb4e4b4c5cs5g5a5bb5) (f3fs3gs3cs4eb4e4b4c5d5g5a5bb5)) (chord-contraction/expansion 4 12-tone-field :chord t :position '(0 5)) => ((f3fs3gs3c4d4e4b4cs5eb5g5a5bb5) (e3fs3gs3c4d4f4b4cs5eb5g5a5bb5) (f3fs3gs3c4d4e4b4cs5eb5g5a5bb5) (e3fs3gs3c4d4f4b4cs5eb5g5a5bb5) (f3fs3gs3c4d4e4b4cs5eb5g5a5bb5)) ;;;; with different intervals (chord-contraction/expansion 4 12-tone-field :chord t :interval 11) => ((f3fs3gs3c4d4e4b4cs5eb5g5a5bb5) (fs3gs3c4d4e4e4b4b4cs5eb5g5a5) (gs3c4d4e4e4f4bb4b4b4cs5eb5g5) (c4d4e4e4f4g4gs4bb4b4b4cs5eb5) (d4e4e4e4f4g4gs4bb4b4b4b4cs5)) (chord-contraction/expansion 4 12-tone-field :chord t :interval 7) => ((f3fs3gs3c4d4e4b4cs5eb5g5a5bb5) (fs3gs3c4c4d4e4b4cs5eb5eb5g5a5) (gs3c4c4cs4d4e4b4cs5d5eb5eb5g5) (c4c4cs4d4eb4e4b4c5cs5d5eb5eb5) (c4cs4d4eb4e4g4gs4b4c5cs5d5eb5))
November 29, 20186 yr Looks interesting. The function seems to work. I tryed some ideas with 3 or 4-note chords. It's easier to figure out what it does. What is the musical idea behind it ? What's the musical purpose? Any example in the context of a composition? Best, Julio
November 30, 20186 yr Author hi julio it's too complicated to share the code...the FUNCTION is made for a specific idea of the work (not common), so it's made for MY need... here is a short sketch of the work... (part of it) a) generating a pitch-sequence => by using a 12-tone-seq + its expansion by a sorting-algorithm (with GEN-SORT) => an INTERVAL-order mutates to a SCALE (see the list-plot) b) pitches are projected on a sequence of symmetrical expanding/compressing FIELDS (with CHORD-CONTR...) => you see how the pitch-seq is contracted/exapnded in "space" - result is a kind of interference of this processes => at the end you see (in list-plot) that the interference is going more and more to ONE LEVEL - to a SCALE - so its a kind of inside/out. the inherent structure, the inherent process/order is more and more recognizable during the process (start with compr/exp. 12-tone-row to the simple SCALE) the project is a bit larger. this sequence (which rhythm is based on a binary-event-filter (data of a jpeg of an artist)) is only the structural background (some ideas developed by LACHENMANN) - on this NET (the score you see) there will be other GESTALTS/MOTIFS etc... because my needs are such specific to my and my idea - most of the functions i had to code for myself, or modify/enlarge the OPMO functions, great that this is possible on this platform. sorry a bit complicated and i can't not describe it properly with a few words 🧐
November 30, 20186 yr Dear André, Thank you for the detailed explanation. In the mind of the composers there is a lot of not so evident processes. This is deep. All the best, Julio
December 1, 20186 yr I will share whatever I can as soon as I can. I'm writing (notating) everything by hand ☠️ when composing and arranging. I have used OM since day 1 and before that SCOM for many years. Still I have not learned much Lisp mainly caused by lack of time. I use these tools mainly for chaotic experimenting I would say. I have just quit working and is now a happy retired and hope to be able to spend more time wit OM and Lisp. /Lasse
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