• ### Similar Topics

• By terekita
Hello,

For various reasons, I need to start with rhythms defined in one time signature and remap them. I'm having trouble doing this because of what happens to ties when you use omn :length (though I realize they are being collected under :articulation).

In this case, I'm taking bars of 4/4 regrouping into bars of 2/4.

(setf myr '( (s s -s s -e s s -s s -e t t t t s s) (e e_q -h))) (setf tr (omn-to-time-signature myr '(2 4)))
Now I take the result of the above and assign it to a new variable ( this would be the same as (setf foo tr) ):
(setf foo '((s c4 c4 - c4 -e s c4 c4) (-s c4 -e t c4 c4 c4 c4 s s) (e c4 c4 tie q) (-h)))
As you can see, there is a tie in the third bar.

Now, how can I extract that rhythm so that I can apply to another set of pitches?

If I do the following, I no longer have the tie represented in the rhythm:
(omn :length foo) ;; results in ;; ((1/16 1/16 -1/16 1/16 -1/8 1/16 1/16) (-1/16 1/16 -1/8 1/32 1/32 1/32 1/32 1/16 1/16) (1/8 1/8 1/4) (-1/2)) ;; i.e., no tie in the third bar
Also, if I try to span the rhythm onto another set of pitches, I again get a result that is missing the tie:
(setf my-pitches '(c4 d4 e4)) (make-omn :length foo :pitch my-pitches)
What I'd really love is to get back a list of lengths that is like my original list, just regrouped in new time signatures. So, ideally something like:
(setf myr '( (s s -s s -e s s -s s -e t t t t s s) (e e_q -h))) ;; imaginary function (regroup-to-two-four myr) ;;would result in the following: ;; ((s s -s s -e s s)(-s s -e t t t t s s)(e e_q)(-h))
Finally, I should add that in a related problem, I need to extract the number of attacks in a bar after it has been regrouped. So, for this reason again, I need to figure out how to extract the rhythm while preserving ties and not re-attacking tied notes.

I'd very appreciate and thank you kindly for any assistance in doing this.

Thanks very much, Michael
• By terekita
Hello,

When I take the following:
(setf lens '((e = = e tie)(e e e e))) (setf notes '((c4 d4 = d4)(d4 g4 = =))) and then call make-omn

(make-omn :length lens :pitch notes) the tie at the end of the first bar is not preserved. Nor is it if I instead have the tie at the end of the first bar of the notes list (or at the end of the first bar in both lists).

What is the proper way to construct an omn list from separate lengths and pitches such that ties are preserved? In this case I am trying to create the equivalent of the following:
(setf test '((e c4 d4 = d4 tie)(e d4 g4 = =)))
thanks very much, Michael

• By AM
;;; FUNCTION: for some coding-cases i needed THIS function, to keep the OMN-notation ;;; and not to change to RATIO (otherwise i got strange results in NOTATION because the "ties are gone") (defun length-invert** (length-val) (append (compress (list '- length-val)))) ;;; EXAMPLES ;;; new => keeps OMN (length-invert** (car '(q e4 mp))) => -q ; in this case i wanted to keep the format with tie (length-invert** (car '(3q_q e4 mp))) => -3q_q ;;; original => changes to ratio (length-invert (car '(q e4 mp))) => -1/4 ; no tie here! i was in trouble :-) (length-invert (car '(3q_q e4 mp))) => -1/3
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