用程式碼寫音樂 - Sonic Pi 教學 2

Video: https://youtu.be/0kccvDX9lqQ

這部影片的靈感是來自好和弦在前幾週的直播，如果沒看過的話可以趕快到資訊卡裡頭看看！好和弦一直是我很喜歡的 YouTube 頻道之一，甚至連我開頭音樂都是用好和弦推薦的 PixiTracker 做出來的。

Sonic Pi 是由 Sam Aaron 與 Raspberry Pi Foundation 協作開發的軟體，可以透過 live coding 的方式來做音樂，最初用在教學音樂課跟程式理論上，不過隨著功能越來越多，你甚至可以用它來做現場演奏。而且為了讓初學者可以快速上手，這個軟體在語法上以及環境上下了非常大的功夫，所以寫起來也相當直覺，馬上就可以看到成果。

第二部我們繼續學習 Sonic Pi 的基本功能，包含好用的 tick, spread, sync、函數、隨機等等，在創作上有更豐富的元素等著我們使用。

Transcript

1. 愷開學程式
   Sonic Pi 基礎教學 - 2
   

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2. 數拍子
   tick
   live_loop :tick1 do
   play chord(:c4, :major).tick
   sleep 0.25
   end
   每次呼叫後會自動 +1
   live_loop :tick1 do
   play scale(:c4, :major).tick
   play scale(:c4, :major).tick
   sleep 0.25
   end
   chord(:c4, :major).each do |note|
   play note
   sleep 0.25
   end
   scale(:c4, :major).each do |note|
   play note
   sleep 0.25
   end
   

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3. live_loop :my_tick do
   puts tick #0
   puts tick #1
   puts tick #2
   puts look #2
   end
   

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4. 命名 tick
   live_loop :tick1 do
   play scale(:c4, :major).tick(:unique_name)
   play chord(:c4, :major).look
   sleep 0.25
   end
   

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5. 取得目前的 beat，但不增加 tick
   look
   live_loop :tick1 do
   play scale(:c4, :major).tick
   play chord(:c4, :major).look
   sleep 0.25
   end
   current_beat = tick
   tick += 1
   play scale(:c4, :major)[current_beat]
   play chord(:c4, :major)[current_beat]
   

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6. 方便建立節奏、音符的函數
   ring
   notes = ring(:g4, :e4, :e4, :f4, :d4, :d4, :c4, :d4, :e4, :f4, :g4, :g4, :g4)
   sleeps = ring(0.25, 0.25, 0.5, 0.25, 0.25, 0.5, 0.25, 0.25, 0.25, 0.25, 0.25, 0.25, 0.5)
   live_loop :name do
   play notes.tick
   sleep sleeps.look
   end
   

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7. 定義函數
   define
   define :play_note do |note|
   play note
   end

   play_note :e5
   

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8. 組合技
   （進階）用 ring 與 define 自製節奏！
   define :create_my_beat do |tempo|
   return ring(*tempo.split("").map { |beat| beat == "*" })
   end
   my_tempo = "*--*--*-" # ring (true, false, false, true, false, false, true, false)
   

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9. my_tempo = create_my_beat("*--*--*-")
   melody = ring(:a5, :c6, :a5, :a5, :c6, :a5, :a5, :c6, :a5, :b5, :a5, :g5)
   live_loop :my_beat do
   if my_tempo.tick(:name) then
   sample :drum_heavy_kick
   play melody.tick(:name1), release: 0.25
   end
   sleep 0.125
   end
   實際應用（Shape Of You）
   

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10. 創造神奇節拍（輾轉相除法）
    spread
    spread(1,8) = (ring true , false, false, false, false, false, false, false)
    spread(2,8) = (ring true , false, false, false, true , false, false, false)
    spread(3,8) = (ring true , false, false, true , false, false, true , false)
    spread(4,8) = (ring true , false, true , false, true , false, true , false)
    spread(5,8) = (ring true , false, true , false, true , true , false, true)
    spread(6,8) = (ring true , false, true , true , true , false, true , true)
    spread(7,8) = (ring true , false, true , true , true , true , true , true)
    spread(8,8) = (ring true , true , true , true , true , true , true , true)
    

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11. live_loop :melody do
    sample :drum_heavy_kick, amp: 2 if spread(2, 4).tick
    sample :drum_cymbal_open if spread(5, 8).look
    play scale(:a4, :major_pentatonic, num_octaves: 2).choose() if
    spread(6, 13).look
    sleep 0.25
    end
    隨便用用看
    

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12. 佛系作曲
    隨機
    use_random_seed 2
    rand(100)
    rrand(100, 1000)
    choose()
    shuffle()
    one_in(4)
    

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13. live_loop :random_dorian do
    play scale(:c5, :dorian).choose(), release: 0.7
    sleep rrand(0.25, 1)
    end
    live_loop :chorus do
    [6, 4, 1, 5].each do |d|
    6.times do
    use_synth :blade
    play (chord_degree d, :c, :major, 3).shuffle().take(3).choose()
    sleep 0.25
    end
    end
    end
    live_loop :drum do
    sample :drum_heavy_kick if one_in(2)
    sample :drum_cymbal_soft if one_in(6)
    sample :elec_cymbal, amp: 0.25
    sleep 0.25
    end
    佛系作曲
    

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14. live_loop :drum do
    sample :drum_heavy_kick
    sleep 1
    end
    live_loop :melody do
    sync :drum
    play :c4, release: 0.25
    sleep 0.25
    play :d4, release: 0.25
    sleep 0.25
    play :e4, release: 0.25
    sleep 0.25
    end
    sync
    和其它聲部同步
    

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15. sound effect 玩起來！
    FX
    with_fx :reverb, room: 1 do
    notes.each_with_index do |n, i|
    use_synth :beep
    play n, amp: 0.7, release: 0.4
    sleep 0.25
    end
    end
    with_fx :echo do
    notes.each_with_index do |n, i|
    use_synth :beep
    play n, amp: 0.7, release: 0.4
    sleep 0.25
    end
    end
    

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16. • distortion
    • compressor
    • ...
    更多音效可參考官方文件！
    

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17. 參考官方教學
    還有更多玩法！
    

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18. 使用 Sonic Pi 撰寫和弦與節奏
    why not - 無法度按奈
    

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