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  • Daniel Ross 09:42 on June 6, 2016 Permalink | Reply
    Tags: slippery chicken symposium   

    I did a recording session with the disklavier on Friday. Velocity 90 is massive. Don’t go above 90.

    • Michael Edwards 12:19 on June 6, 2016 Permalink | Reply

      anyone who’s setting their amplitudes before the call to midi-play can make sure their velocities don’t get too high via this hard-limiting approach when calling midi-play:

      (midi-play +jitterbug+ :force-velocity
      	   #'(lambda (event)
      	       (min 100 (floor (* (amplitude event) 127)))))
      • Michael Edwards 12:23 on June 6, 2016 Permalink | Reply

        or perhaps simpler and not hard-limiting, this will automatically range over 100 instead of 127, assuming that your events’ amplitude values range up to 1.0

        (midi-play +jitterbug+ :force-velocity
                   #'(lambda (event)
                       (floor (* (amplitude event) 100))))
  • Michael Edwards 08:34 on May 27, 2016 Permalink | Reply
    Tags: auxiliary notes, post-generation, slippery chicken symposium   

    Some of you will already know the rm-repeated-pitches method. This finds repeating pitches in any or all voices of a slippery-chicken object and replaces them with other pitches from the current set. Of course what this is doing is ironing out some of the problems inherent to algorithmic pitch selection, and slippery chicken’s in particular.

    For the Goldsmith’s project next month I’ve developed a related method called add-auxiliary-notes. This tries to deal with some of the static pitch structures that arise out of limited but extended harmonic fields. It analyses slippery-chicken voices phrase by phrase to find the most frequently used notes, then changes some of them (according to an activity-levels object) to auxiliary notes (up a semitone by default but any and varied intervals are possible). It’s already available on the SVN server so those of you who want it will find it along with documentation in the file slippery-chicken-edit.lsp after doing (update-app-src …)

    • Daniel Ross 16:19 on June 2, 2016 Permalink | Reply

      I’m getting the following error with this new add-aux–notes method:
      (LET* ((POC
      (PITCH-OR-CHORD E)))

      • Daniel Ross 16:19 on June 2, 2016 Permalink | Reply

        Execution of a form compiled with errors.
        (LET* ((POC
        (IF WRITTEN
        (PITCH-OR-CHORD E)))
        (IS-CHORD E)
        Compile-time error:
        The LET* binding spec (IF (IS-CHORD E)
        COLLECT (FREQUENCY P))) is malformed.
        [Condition of type SB-INT:COMPILED-PROGRAM-ERROR]

      • Michael Edwards 16:40 on June 2, 2016 Permalink | Reply

        that code works fine for me. I can’t see an error in there and my Lisp doesn’t complain when I compile event.lsp

        I think you’ll have to send the offending code

        • Daniel Ross 16:45 on June 2, 2016 Permalink | Reply

          It’ll take me ages to get something you an run on your machine….
          Isn’t it just a misplaced bracket in the get-frequency method? (A close paren missing on line 7 and on line 10 instead)

          • Michael Edwards 17:08 on June 2, 2016 Permalink | Reply

            I know what you mean but I can’t see an error there. Maybe a download problem? This is what I’ve got and it runs fine for me:

            (defmethod get-frequency ((e event) &key written force-list average)
              (if (is-rest e)
                  (let* ((poc (if written
                                  (written-pitch-or-chord e)
                                  (pitch-or-chord e))))
                    (if (is-chord e)
                        (if average
                            (/ (loop for p in (data poc) sum (frequency p))
                               (sclist-length poc))
                            (loop for p in (data poc) collect (frequency p)))
                        ;; single pitch
                        (if force-list (list (frequency poc)) (frequency poc))))))
            • Daniel Ross 17:23 on June 2, 2016 Permalink

              That’s nothing like what I have. Will try update-app-src again…

            • Daniel Ross 17:25 on June 2, 2016 Permalink

              Nope, no luck. Still looks like this:
              (defmethod get-frequency ((e event) &key written force-list)
              ;;; ****
              (if (is-rest e)
              (let* ((poc (if written
              (written-pitch-or-chord e)
              (pitch-or-chord e)))
              (if (is-chord e)
              (loop for p in (data poc) collect (frequency p)))
              (if force-list (list (frequency poc)) (frequency poc))))))

            • Michael Edwards 17:34 on June 2, 2016 Permalink

              so your code is different to mine. that’s weird. I’m updating the src at svn-latest. In the meantime just replace your method definition with mine and all should be well.

            • Michael Edwards 17:37 on June 2, 2016 Permalink

              try (update-app-src …) I can definitely see the right version of the method at https://sourced.ecdf.ed.ac.uk/projects/user/medward2/browser/sc-tags/sc-latest/src/event.lsp

            • Daniel Ross 08:41 on June 3, 2016 Permalink

              Cool, that works now. Thanks!

  • Michael Edwards 13:48 on May 25, 2016 Permalink | Reply
    Tags: pedalling, piano, slippery chicken symposium   


    If you who read facebook slippery chicken group posts you may remember this one about pedalling:

    “Those of you working on piano pieces: as of yesterday, if you add one of the three pedal marks ‘ped, ‘ped-up, or ‘ped^ you’ll get the correct controller information written to your MIDI files for free—in other words, during MIDI playback the sustain pedal should work.

    If you want to set the controller message of an event yourself, just e.g.
    (push '(1 64 127) (midi-control-changes event))
    where the first 3-element list there is (midi-channel controller-number value). 64 is the sustain pedal controller number; 127 will depress and 0 will release.

    If you need this functionality do (update-app-src …)”

    Just wanted to update this to mention that this will also work with the ‘uc and ‘tc marks (una corda / tre corde) and the ‘sost and ‘sost-up marks (middle / sostenuto pedal), i.e. not only will the pedal marking appear in the score but the MIDI controller data will be written when you call midi-play.

  • Michael Edwards 09:58 on May 20, 2016 Permalink | Reply
    Tags: lachenmann, nono, slippery chicken symposium   

    I have never quite been able to separate my sadness at the loss of Luigi Nono from a feeling of greater awareness, of happiness and gratitude that he ever existed—and ever existed in our proximity. And despite the loneliness which I share with so many others who loved him, I feel, when I think of him, a unique sense of the triumph of art and a hope that its restless force will endure in times of apparent hopelessness.

    Helmut Lachenmann
  • Daniel Ross 09:46 on May 20, 2016 Permalink | Reply
    Tags: slippery chicken symposium   

    slip chick symp

    slippery chicken symposium

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