newbie here 🙂
I'm just starting with OM and playing around with the tutorials.
I slightly changed tutorial #4 and run into something strange.
If i run the script as posted below, all works as expected. But when i change the function reverse to nreverse (and nreverse is the oficially documented name of the function)
the omn result will leave the right hand empty. Why ist that? And why does reverse work as i expect it to work?
And, another thing: i dont understand what the term seed will do. Will it make random functions behave always the same as long as the seed is the same?
...and what does the number following the seed mean?
Thank you !!
(setf pitches (gen-repeat 5 '(c4 cs4 fs4 g4 c5 cs5))) (setf transposed-pitches (gen-repeat 5 (pitch-transpose -24 pitches))) (setf lengths (span pitches '(e))) (setf lengths-rests (length-weight lengths :weight '(2 1) :seed 12)) (setf left-lengths (reverse lengths-rests)) (setf piano-righthand (make-omn :length lengths-rests :pitch pitches :velocity'(mp))) (setf piano-lefthand (make-omn :length left-lengths :pitch transposed-pitches :velocity '(f))) (setf timesigs (get-time-signature left-lengths)) (def-score lesson-4 (:key-signature 'chromatic :time-signature '( 5 8 ) :tempo 190 :layout (piano-layout 'piano-rh 'piano-lh)) (piano-rh :omn piano-righthand :channel 1 :sound 'gm :program 'acoustic-grand-piano) (piano-lh :omn piano-lefthand) )
Somewhat stupid question but I do not find a function that would allow me to reorder a sequence of pitches.
Let me explain, on a forum where Messiaen's limited transposition modes are discussed, I wanted to show that with Opumodus we could very easily analyze the modes and recreate them. I have no problem with those who are in total symmetry and divisible by two, but if I take the mode 3: (c4 d4 eb4 e4 gb4 g4 ab4 bb4 b4), using the function pitch-transpose-start I get in the end the mode but according to the postponement of the intervallic structure on c4 d4 ab4 is => ((c4 e4 gs4) (d4 fs4 bb4) (eb4 g4 b4)). I tried to reorder with the function pcs-normal-order the mode is reordered but with however the c4 in last position: (d4 eb4 e4 fs4 g4 gs4 bb4 b4 c4). Now, I suppose there is a function that makes it possible to obtain the right disposition. What is it ?
(setf modmessiaen3 '(c4 d4 eb4 e4 gb4 g4 ab4 bb4 b4)) (setf SIMessiaenMod3 (pitch-to-interval modmessiaen3)) ; => (2 1 1 2 1 1 2 1) (setf mod3divide (gen-divide 3 modmessiaen3)) (setf firstmodmessiaen3 (filter-first 3 modmessiaen3)) (setf report3 '(c4 e4 ab4)) (setf rep3 (gen-repeat 3 (list report3))) (setf pch3 (modus (flatten (pitch-transpose-start firstmodmessiaen3 rep3)))) (setf MessiaenMod3 (pcs-normal-order pch3 :pitch)) (setf SIMessiaenMod3a (pitch-to-interval MessiaenMod3)) ; => (1 1 2 1 1 2 1 -11) (setf mod3chordsM (melodize '((c4eb4gb4) (d4gb4bb4) (eb4gb4bb4) (e4g4b4) (gb4bb4db5) (g4b4d5) (ab4b4d5) (bb4gb5) (b4d5gb5)))) (setf analysechords3 (pcs-analysis (integer-to-pitch (modus mod3chordsM))))
In particular, this distorts the analysis of the interstellar structure of mode 3:
of (2 1 1 2 1 1 2 1) I get (1 1 2 1 1 2 1 -11)
Besides, there is probably a more efficient script than the one I tried?
PS : In fact, I realize that the function pcs-normal-order is not adapted at all according to the modes.