kenny_g.rb: Making Ruby Write Smooth Jazz (Open Source Bridge 2015)

For too long, computers have been shut out of the red-hot music-to-listen-to-while-relaxing-in-the-bathtub genre. Today, that all changes. Our smooth-jazz-as-a-service startup is primed to disrupt this stale industry. All we need is a little Ruby and we'll make automated musical magic.

Transcript

1. kenny_g.rb: Making Ruby write smooth jazz Tim Krajcar
2. TimKrajcar https://www.flickr.com/photos/can_eldem/6929385615
3. TimKrajcar https://www.flickr.com/photos/can_eldem/6929385615
4. –Johnny Appleseed https://www.dropbox.com/s/8t7mg4gikhx0d5p/Screenshot %202015-06-09%2019.12.34.png?dl=0
5. –Johnny Appleseed
6. –Johnny Appleseed bit.ly/ OSBridgeNRJobs
7. TimKrajcar Jason Clark - Testing the Multiverse Wednesday 3:45pm - B301 Zoe Kay - Venturing into the Spooky Science of Ruby Thursday 3:45pm - B301 Ward Cunningham - Learning and Knowing with Federated Wiki Jonan Scheffler - Hacking Minecraft
8. TimKrajcar Tim Krajcar's twitter handle is: @TimKrajcar
9. TimKrajcar
10. TimKrajcar story time
11. TimKrajcar https://www.flickr.com/photos/gruenewiese/15668094425
12. TimKrajcar https://www.flickr.com/photos/vironevaeh/4494702797/
13. TimKrajcar audience participation!
14. https://www.flickr.com/photos/kimli/1879624559/
15. TimKrajcar IS HE A WIZARD??
16. TimKrajcar https://www.flickr.com/photos/mhx/16419218393
17. TimKrajcar https://www.flickr.com/photos/mhx/16419218393 I could do that
18. TimKrajcar can it be automated?
19. TimKrajcar can it be automated?
20. TimKrajcar can it make me lots of money without me doing any work?
21. TimKrajcar some background
22. TimKrajcar MIDI Musical Instrument Digital Interface
23. TimKrajcar MIDI = protocol for control
24. TimKrajcar MIDI ≠ audio
25. TimKrajcar MIDI is messages
26. TimKrajcar note on (note, velocity 0-127)
27. TimKrajcar note off (note)
28. TimKrajcar also lots of other things
 (program and control changes, aftertouch, pitch bend, sysex, ...)
29. TimKrajcar
32. TimKrajcar
33. TimKrajcar MIDI is fun!
34. –Johnny Appleseed
35. TimKrajcar the challenge: build a tool that plays delightful piano music based on a series of four notes
36. TimKrajcar the challenge: build a tool that plays delightful piano music based on a series of four notes
37. TimKrajcar the challenge: build a STARTUP that plays delightful piano music based on a series of four notes
38. –Johnny Appleseed
39. TimKrajcar first strategy: algorithmic harmony
40. –Johnny Appleseed
41. –Johnny Appleseed
42. TimKrajcar algorithmic music = not very relaxing https://www.youtube.com/watch?v=TAHamdXqTTI
43. TimKrajcar this is really hard
44. TimKrajcar user persona!!
45. https://www.flickr.com/photos/santheo/531632789
46. https://www.flickr.com/photos/santheo/531632789 STEVE
47. https://www.flickr.com/photos/santheo/531632789 STEVE STEVE'S DUCK
48. TimKrajcar what to do?
49. TimKrajcar strategy inspiration: reddit™ (reddit doesn't like it if you use their logo without a license so I'm not using it) REDDIT and the ALIEN Logo are registered trademarks of reddit inc.
50. TimKrajcar "[...]when logged in as an admin, a third field appeared that allowed the team to enter a custom user name that would automatically be registered for an account upon hitting submit." http://venturebeat.com/2012/06/22/reddit-fake-users/
51. TimKrajcar like any good startup, we will CHEAT!
52. TimKrajcar like any good startup, we will CHEAT!
53. TimKrajcar like any good startup, we will utilize pre-recorded interactions to simulate real- time generative algorithms!
54. TimKrajcar play back pre-recorded "transitions" between chords
55. –Johnny Appleseed
56. –Johnny Appleseed
57. –Johnny Appleseed
58. –Johnny Appleseed
59. –Johnny Appleseed
60. –Johnny Appleseed we need to write transitions for all of these?!
61. TimKrajcar BIG MUSIC SECRET!!!
62. TimKrajcar THE SECRET: you just need the relative intervals
63. TimKrajcar transpose using the first note as "zero"
64. TimKrajcar we need to record a "phrase" a short bit of music that transitions from "zero" to an interval
65. TimKrajcar play back and repeat as needed
66. TimKrajcar let's do it
67. TimKrajcar https://github.com/tkrajcar/kenny_g.rb
68. TimKrajcar tech demo 1: all the keys
69. TimKrajcar require "midi" @output = UniMIDI::Output.use(:first) MIDI.using(@output) do velocity 64 (0..127).each do |n| play n, 0.01 end end
70. TimKrajcar tech demo 2: recording our phrases
71. TimKrajcar saving notes! sounds like a job for MIDI!
72. –Johnny Appleseed
73. –Johnny Appleseed
74. –Johnny Appleseed
75. TimKrajcar we'll just make up our own standard
76. TimKrajcar big news!!
78. TO HACKER NEWS!!
79. TimKrajcar [ { "note": 60, "velocity": 80, "starting_time_offset": 0.677646, "duration": 0.248938 }, { "note": 67, "velocity": 65, "starting_time_offset": 0.920729, "duration": 0.27753 }, { "note": 64, "velocity": 72, // ...
80. TimKrajcar tech demo 3: playback!
81. TimKrajcar MIDI.using(@output) do @notes = JSON.parse(File.read("sample.notejs")) @offset = 0 @notes.each do |note| sleep(note["starting_time_offset"] - @offset) play note["note"], note["duration"] @offset += note["duration"] end end
82. TimKrajcar https://www.flickr.com/photos/deivis/2300233581/
83. TimKrajcar https://www.flickr.com/photos/deivis/2300233581/ DO NOT SHIP IT
84. TimKrajcar MIDI.using(@output) do @notes = JSON.parse(File.read("sample.notejs")) @offset = 0 @notes.each do |note| sleep(note["starting_time_offset"] - @offset) play note["note"], note["duration"] @offset += note["duration"] end end
85. TimKrajcar tech demo 4: playback better!
86. TimKrajcar MIDI.using(@output) do @notes = JSON.parse(File.read("sample.notejs")) @messages = @notes.flat_map do |note| [ {type: :note_on, note: note["note"], velocity: note["velocity"], at: note["starting_time_offset"]}, {type: :note_off, note: note["note"], at: note["starting_time_offset"] + note["duration"]} ] end @messages.sort! do |a, b| a[:at] - b[:at] end
87. TimKrajcar @offset = 0 @messages.each do |message| sleep(message[:at] - @offset) if message[:type] == :note_on note message[:note], velocity: message[:velocity] else note_off message[:note] end @offset += sleep_duration end
88. TimKrajcar tech demos complete! almost ready for funding!
89. TimKrajcar the patent-pending kenny_g.rb algorithm
90. TimKrajcar step 1: convert user-provided chords to relative intervals, with the first chord as 0
91. TimKrajcar input: F, A, C, D relative intervals: [0, 4, 7, 9]
92. TimKrajcar step 2: convert list of intervals to list of phrase transitions
93. TimKrajcar input: [0, 4, 7, 9] phrase transitions: {0, +4}, {4, +3}, {7, +2}
94. TimKrajcar step 3: play back pre-recorded phrases, transposed into starting key
95. TimKrajcar DEMO!
96. TimKrajcar thanks!