Jump to content
Sign in to follow this  
torstenanders

Opposite of gen-swallow for functions that add notes like length-divide?

Recommended Posts

The function LENGTH-DIVIDE and friends are a useful device for introducing some rhythmic variation to some material. However, when the processed sequence is a full OMN expression (see example below), then the added notes cause all other parameters to shift forward (additional parameters are added at the end by looping). For introducing only a slight variation to some existing material (e.g., motif) these functions are therefore not so useful, because this shift of all parameters to basically "fill" the new added notes with pitches etc. greatly change the varied material for a listener.

(length-divide 1 2 '(q f3 leg+m1 q ab3 leg e c4 leg bb3 leg ab3 leg g3))

 

Basically, this is the opposite situation of the situation addressed by swallowing. Swallowing (e.g., with GEN-SWALLOW and the swallow argument of many other functions) avoids the shift of parameters like pitch etc. that would result from removing notes and turning them into rests. For addressing the situation above properly we would need something like the opposite of swallowing, some way to fill in parameters like pitch etc. for new notes to avoid shifting existing notes. I hope my explanation makes sense and you can see why something like the opposite of swallowing would be useful for functions that add notes to some input material.

 

Now, the tricky question is of course, what parameters (pitch etc.) should be added in such cases. Musically useful and common in the classical literature would be, e.g., repeating the parameters (pitch etc.) of the predecessor note (though that might be a bit too simplistic and annoying at times) or somehow interpolating some pitch gap between the previous and next note with a little scale or arpeggio and only repeating the other parameters like articulations (resulting in some variation that is likely most similar to the input material, so it would be good to have that as an option).  If the pitch interval between the two original notes is too small to add some pitch in between for the new now (or as an option in general for variety), it would also be good  to add some ornamentation (e.g., using PITCH-ORNAMENT), but for a close similarity between the original material and the variation it would be best as an option to apply such ornamentation only to the newly added notes, not all notes. Of course, other options could also be useful for variations that vary the input material a bit more strongly, e.g., some random pitch for the new notes within certain interval bounds.

 

Does some function that kind of is the opposite of GEN-SWALLOW in that it adds parameters like pitches for subdivided rhythmic values (to avoid the shifting) sound like a good idea?

 

The idea with the interpolation of gaps could be implemented by turning the original duration values and pitches into some envelope and then reading that envelope with the new rhythmic values. So, that is rather strait forward. However, that would not allow for some ornamentation, because such algorithm would not recognise which notes are new that should be ornamented.

 

Any other idea perhaps? Thanks! 

Share this post


Link to post
Share on other sites

Possible solution to 'fill' the added values:

:repeat and :ornament

 

This shouldn't be difficult to implement.

Share this post


Link to post
Share on other sites

Do you mean as an option for the function length-divide? That would be great, but my preferred solution would be to have some extra function complementing gen-swallow for added notes -- which then could be called within functions like length-divide -- because that would be a generic solution for all sorts of functions that somehow add notes. The slightly tricky bit would perhaps be for the function to notice which are the new notes, so it should likely get as an input both the original material and the material with the added notes to find out... 

I would be happy to help sketching such a function...

One approach might also be if functions adding notes would somehow mark such notes with some custom articulation only used for that purpose, but that would only work for full OMN results, not single parameters (e.g., length-divide supports single length values). An alternative idea would be for functions adding notes to simply specify the positions in the resulting list that they added (with some special notation for nested lists). 

Anyway, if it would be much more simply to refactor only length-divide and friends, that would be welcome too...

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

  • Similar Topics

    • By torstenanders
      Revising some older code of my I noticed that the function length-divide changed its behaviour somewhat and became more likely to cause an error.
       
      In a previous version, where the arguments count and divide where given separately, it was possible to set the count to some very high number, say, 1000, simply to mean that all notes the function can split (depending on its other arguments) will be split. 
       
      Meanwhile, the function have been revised to introduce control over intervals (thank you 🙂), but since then it seems it is not possible anymore to set an arbitrarily high count value anymore. For example, the following code now results in an error. I would prefer the previous behaviour, if only because it is more forgiving and stable.
       
      (length-divide '(1000 2) '(q ab3 num1+leg c4 leg e ab3 leg g3 leg ab3 num1+leg c4 leg)) Error: The value ab3 is not of the expected type sequence.  
      In case it helps: my debugger tells me the functions gen-repeat and then maybe-section are called (perhaps within a nested function of length-divide* ?) with an argument sequence bound to ab3 (i.e. a plain pitch), and a call (length ab3) then causes this error. 
       
      Thank you!
       
      Best,
      Torsten
    • By Frederic
      Hello all, 
       
      I'm coming from the javascript development world. Here are few musical ideas. Is there a way to implement them thanks to Opusmodus ? 
       
      - play a sequence of notes in 30 seconds:
      in javascript, it could be pseudo-coded like this: 
       
       setTimeout(function(){ play('c4 d4 e4 f4 g4'); }, 3000);   
      - play a sequence of notes at a specific event.
      in Javascript/jQuery, it is very easy to code anonymous functions that would wait for a specific event to be triggered. Some examples I have in mind:
       
      play 'do ré mi' at bar 4
      $('4th bar').on(function() { play('c5 d5 e6');});  
      play 'do ré mi' each time note f5 is played
      $('f5').on(function() { play('c5 d5 e6');}); repeat the note + octave when f5 is played
      $('f5').on(function(this) { play(this + this.octave(1));});  
      In other words: is it possible to trigger an anonymous function with opusmodus, so that a musical phrase will be played at specific event ? 
       
       
      Thanks for clarification, best !
    • By JulioHerrlein
      In the jazz world, Barry Harris came up with the idea of harmonizing a bebop scale.
      Combining a C6 (C, E, G, A) and a Bdim7 (B, D, F, Ab) chords, we have this scale:
       

       
      From this stantpoint we can alternate tonic and dominant sounds, like this:
       

       
      Every pair of chords have all the 8-note set.
      The notes C,E, G and A are always harmonized with a C6 chord.
      The notes D, F, Ab and B are always harmonized with a Bdim7 chord.
       
      So, from the point of view of sets, there is no problem.
       
      WHAT IS NEEDED:
       
      I want a way to start FROM the melody, and then make a four part block harmonization with this (or any other) harmonic system
       from the melody as an OMN expression.
       
      So, I need a way to filter the notes to aply the right chord:
       
      FOR EXAMPLE:
       
      For the notes C, E, G and A
      If the note is an C (in any register), I will apply a chord like , I will add the notes A, G and E, below the melody.
      If the note is an  (in any register), I will apply a chord like , I will add the notes G, E and C, below the melody.
      And so on...
      For the notes D, F, Ab and B:
       
      If the note is an B (in any register), I will apply a chord like , I will add the notes Ab, F and D, below the melody.
      And so on:
       
      So, to make any procedure:
       
      I need first find a way to apply a specific procedure only over the notes I want, over all the C notes, all the B notes, etc.
       
      How to filter from an OMN expression ?
       
      All the best !
      Julio
       
       
       
       
×
×
  • Create New...