Grace notes represented by symbol z?

[torstenanders]

I would like to algorithmically process rhythms that contain grace notes. The function omn turns grace notes into 0 lengths, which is useful.

 

  (omn :length '((acc 1/8 1/8) 1/2 1/4))

 

However, I have difficulties translating them back after whatever processing of the rhythm. The function make-omn turns 0 lengths into the symbol z, but this symbol is not supported by snippet preview.

 

   (make-omn :length (omn :length '((acc 1/8 1/8) 1/2 1/4)))

 

What am I missing here?

 

Best,

Torsten

 

PS: Apologies for submitting so many messages.

 

 

[opmo]

You can processes OMN lengths but it is not that easy. To do that you need to use DISSEMBLE-OMN and then MAKE-OMN.

(apply 'make-omn
       (disassemble-omn '(q c4 e d4 acc e acc h f4 q g4)))

 

One day I will make documentation how to do that.

Here is a short example:

(defun add-len (omn add)
  (let ((plist (disassemble-omn omn)))
    (setf (getf plist :length)
          (loop for i in (getf plist :length)
            collect (+ add i)))
    (apply 'make-omn plist)))

(add-len '(q c4 e d4 f4 h g4) '1/8)
=> (q. c4 q d4 f4 he g4)