* WAVEing at Repetitive
:PROPERTIES:
:type:     title
:author:   Zachary Kanfer
:END:
Repetitive Repetitive
Music
* Bored at home
** "Antistress" app
[[file:~/Downloads/antistress-main3.jpg][zp-image]]
* I want more!
** faster! slower!
** more beats!
** undo!
** different scales!
* Enter: Emacs
:PROPERTIES:
:type:     title
:END:
* WAVE files?
** [[https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vbWVkaWEucmJsLm1zL2ltYWdlP3U9JTJGZmlsZXMlMkYyMDE2JTJGMDUlMkYwOCUyRjYzNTk4MzI4MzA0MDc1OTE5NS04MDIyMzc0OTlfbWljaGFlbC1waGVscHMuanBnJmhvPWh0dHBzJTNBJTJGJTJGYXo2MTY1Nzgudm8ubXNlY25kLm5ldCZzPTQ0MiZoPTZlZTQwYzVhNmI0ZWFjNjBlMzA0MzVkMTFjYTFkNTRiZjkzYjNmM2ZhNmQ3Y2ZkNGQzOWVhODZiODUzODdiYjMmc2l6ZT05ODB4JmM9ODc4MzU2MDM2IiwiZXhwaXJlc19hdCI6MTY1MjM4MjU5Mn0.xIvOCNadJObm8X6TRtOQM_GcIbpdxBhRTgfUpoWS03w/img.jpg?width=1200&height=628][zp-image]]
* WAVE -- a
musical  file format
* WAVE -- an                                                          :slide:
annoying file format
** one-byte numbers are unsigned integers                            :slide:
** two-byte numbers are signed integers                              :slide:
* WAVE -- an
annoying file format II
** little-endian by default! ((0 1) == 10)                           :slide:
** The WAVE spec allows big-endian as well.                          :slide:
But...
** Emacs can only play little-endian data.                           :slide:
* WAVE -- an                                                          :slide:
annoying file format III:
duplicate data
** SAMPLE-RATE
** NUMBER-OF-CHANNELS    (1: mono, 2: stereo)
** BITS-PER-SAMPLE                                                   :slide:
** BLOCK-ALIGN:                number-of-channels * bits-per-sample / 8 :slide:
** BYTE-RATE:    sample-rate * number-of-channels * bits-per-sample / 8 :slide:
* WAVE -- an
annoying file format IV
** Last part of the file is "data".                                  :slide:
** "The actual sound data".                                          :slide:
* What is data?
** [[https://i.ytimg.com/vi/9FqFm_vmVnE/maxresdefault.jpg][zp-image]]
* Data!
** Turns out it's the height of the waveform at each sample.
** [[https://upload.wikimedia.org/wikipedia/commons/b/bf/Pcm.svg][zp-image]]
* Demo!
:PROPERTIES:
:type:     title
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* Other features                                                      :slide:
** Save to a file!                                                   :slide:
*** Had to make "silent" notes, which are not normally needed.      :slide:
** Different scales!                                                 :slide:
** Terrible-sounding keyboard support
* Things I learned: Emacs
:PROPERTIES:
:type:     title
:END:
* Emacs has buttons!
** (insert-text-button "text")
* Spacing issues!                                                     :slide:
** Unicode has a "zero-width space"! Yay!                            :slide:
** It has width! Boo.
* Ways to play sound...that don't work!                               :slide:
** #'play-sound...                                                   :slide:
*** blocks                                                          :slide:
** Async.el...                                                       :slide:
*** is silent
* A way to play sound...that works!                                   :slide:
** Shell out to native WAVE player                                   :slide:
** ...once.
* Side effects have a big impact on runtime.
:PROPERTIES:
:type:     title
:END:
* Thing I learned: Music Theory
:PROPERTIES:
:type:     title
:END:
* Music theory is NOT easily programmable.
:PROPERTIES:
:type:     title
:END:
* Scale degrees
** [[https://hellomusictheory.com/wp-content/uploads/2019/02/10.8-1024x180.png][zp-image]]
* You don't want to program in scale degrees.
:PROPERTIES:
:type:     title
:END:
* Scale degrees
** [[https://hellomusictheory.com/wp-content/uploads/2019/02/10.8-1024x180.png][zp-image]]
* Intervals
** [[https://chordprogressionblog.files.wordpress.com/2016/09/intervals1.gif][zp-image]]
* You don't want to program in intervals.
:PROPERTIES:
:type:     title
:END:
* Intervals
** [[https://chordprogressionblog.files.wordpress.com/2016/09/intervals1.gif][zp-image]]
* Music is really frequencies.
:PROPERTIES:
:type:     title
:END:
* Solution!
** At a low-level, use frequencies.                                  :slide:
** At a high level, use "semitones up from the root". Translate these to frequencies.
* Future work
** drums
** interactive keyboard
** add overtones (harmonics)
* Thank you!
** [[https://zck.org/emacsconf2020][https://zck.org/emacsconf2020]]
** [[https://emacsnyc.org/][https://emacsnyc.org]]
** [[mailto:zkanfer@gmail.com][zkanfer@gmail.com]]