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Showing results for tags 'chance'.
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Revisiting some of John Cage's compositional techniques
hujairi posted a topic in Score and Notation
Hello, I have been reviewing James Pritchett's The Music of John Cage lately, and was particularly surprised by the detail in which some of the techniques John Cage developed in the 1940s are described such as his "gamut" technique and "chart" technique. I am very curious to see whether you are aware of any attempts to use Opusmodus to create something somewhat similar to these techniques? In theory, the gamut technique is a collection of "sound materials" made before the composition is arranged, and that these sound materials (with varying content, and often containing most of the chords in a piece), while the chart technique is a chart that makes a chart of different possible sounds according to the types of instruments that are used in the piece, only each horizontal axis gives more probability for the appearance of a particular instrument (I wonder if that makes sense). It seems like a good exercise in composition if not anything else, but I'm curious to see how to recreate this in OMN. Otherwise, are there any plans to implement some of John Cage's compositional techniques into OMN's functions? Thanks. -
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;; WHEN PATTERN-MATCH => T ;;; THEN WEIGHETD RANDOM DECIDING THE NEXT VALUE ;;; with :gate/:keyword = extra AND-function ;;; with :evaluate => you could evaluate a function-output directly ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; subfunctions (defun pattern-match (liste pattern) (loop for z in liste with cnt = 0 with pattern_cnt = 0 when (or (equal (nth cnt pattern) z) (equal '? (nth cnt pattern))) do (incf pattern_cnt) and do (incf cnt) else do (setq cnt (setq pattern_cnt 0)) when (equal pattern_cnt (length pattern)) collect 't into bag and do (return (car bag)))) (defun test.pm.omn (seq pattern) (let ((seq (if (omn-formp seq) (cond ((lengthp (car pattern)) (omn :length seq)) ((pitchp (car pattern))(omn :pitch seq)) ((velocityp (car pattern)) (omn :velocity seq))) (append seq)))) (pattern-match seq pattern))) (defun weighted-random (list) (loop for item in list with rand-num = (random (loop for x in list sum (second x))) for add = (second item) then (+ add (second item)) when (< rand-num add) return (first item))) ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; mainfunction (defun test.pm+chance (test.seq pattern values/weights &key keyword gate (evaluate 'nil)) (let ((out)) (setf out (if (and (test.pm.omn test.seq pattern) (equal keyword gate)) (weighted-random values/weights) (append gate))) (if (equal evaluate 't) (eval out) (append out)))) ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; example => works also with OMN etc... (test.pm+chance '(1 2 3 4 5 4 3 5 6 7 2) '(5 ? 3) '((a 0.5) (b 0.15) (c 0.375) (d 0.21))) ;; more examples (test.pm+chance '(1 2 3 4 5 4 3 5 6 7 2) '(5 ? 3) '((a 0.5) (b 0.25) (c 0.25)) :gate 'no-entry :keyword 'no-entry) ;; => key correct (test.pm+chance '(1 2 3 4 5 4 3 5 6 7 2) '(5 ? 3) '((a 0.5) (b 0.5)) :gate 'no-entry :keyword 'whatever) ;; key incorrect ;; example with :evaluate T (test.pm+chance '(1 2 3 4 5 4 3 5 6 7 2) '(5 ? 3) '(((cons 'a 'b) 0.5) ((cons 'c 'd) 0.5)) :evaluate t)