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Change Velocity Repeating Notes

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Hi Everyone,

I'm looking for a method/function which changes the velocity only for notes that are repeating.
In other words, if I have a sequence like this:

'(c4 eb4 g4 ab4 ab4 ab4 d4 eb4)

I would like to be able to create a crescendo/decrescendo or set a custom velocity for just the Ab notes.
In the past I've customised a Pattern Matching function from Stephane to change the velocity for specific note lengths:

(defun velocity-map-omn (map omn &key (otherwise '-))
    (let ((plist (disassemble-omn omn)))
      (setf (getf plist :velocity)
            (pattern-map map (getf plist :length) :otherwise otherwise :swallow t))
      (apply 'make-omn plist))))

And I think this should be very close to what I want, however, I have no idea how to tell OM to process repeating notes only.
Is there anyone who already has a function like this or can steer me in the right direction? Hope this makes sense, any help is very welcome!


- Jor

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like that..?... some code...




(defun replace-velocities-in-a-seq (omn-list &key pitch velocity-list)
     with cnt = 0
     for i in (single-events omn-list)
     when (equal (cadr i) pitch)
     collect (omn-replace :velocity (nth cnt velocity-list) i)
     and do (incf cnt)
     else collect i

     when (> cnt (length velocity-list))
     do (setf cnt 0))))

(replace-velocities-in-a-seq '(e c4 ppppp d4 d4 e4 f4 d4 d4 g4 b4 d4 d4 d4 d4)
                             :pitch 'd4
                             :velocity-list '(p mp mf f ff))

;=> (e c4 ppppp e d4 p e d4 mp e e4 ppppp e f4 ppppp e d4 mf e d4 f e g4 ppppp e b4 ppppp e d4 ff e d4 ppppp e d4 p e d4 mp)

;; if there are more 'd4's then velocity-values, -> it starts again with first velocity-value (= cycle)


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you're welcome!!


i think for specific solutions it helps a lot to learn some LISP-basics (loops/conditionals/car/cons/...), then you have the possibility to make your own additional functions/libraries in OPMO. and OPMO is really great for such things!! 😎




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Books about Common Lisp


For a more music-related introduction to Common Lisp you might want to look at the following books. These books teach algorithmic composition with Common Lisp. The above books introducing only Common Lisp are far more comprehensive on that matter, but you might prefer learning some foundations first within a  musical context.



Morgan, N. & Legard, P. (2015) Parametric Composition: Computer-Assisted Strategies for Human Performance. West Yorkshire, UK: Tonality Systems Press.

Introduces Opusmodus along with some Lisp.



Taube, H. (2004) Notes from the Metalevel. London and New York: Taylor & Francis.
This book introduces the algorithmic composition system Common Music, along with Lisp fundamentals.

Algorithmic Composition: A Gentle Introduction to Music Composition Using Common LISP and Common Music

I have not read this one...
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The best document combining both worlds is likely the following. This was an internal textbook of the algorithmic composition teacher Paul Berg at the Sonology course at the Royal Conservatory of The Hague (the author of the composition system AC Toolbox, https://www.actoolbox.net), but it is unprinted, just a copy of a text processor document for internal use, and difficult to obtain (I only have a hard copy I got from a friend). 


Berg, Paul (n.d.) Elements of Design. An introduction to Programming with Common Lisp. 
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