// September — Earth, Wind & Fire
// 124 bpm, 4/4, key D major. Source: mcgill.
// Generated by strudelify. One cycle = one bar.
setcpm(124/4)

const chords = arrange(
  // intro (10 bars)
  [10, "<[D^7@2 C#m7 Bm7] [C#m7@2 F#m7@2] [D^7@2 C#m7 Bm7] [C#m7@2 F#m7@2] [D^7@2 C#m7 Bm7] [C#7@2 F#m7@2] A11!4>"],
  // verse (16 bars)
  [16, "<[D^7@2 C#m7 Bm7] [C#m7@2 F#m7@2] [D^7@2 C#m7 Bm7] [C#m7@2 F#m7@2] [D^7@2 C#m7 Bm7] [C#7@2 F#m7@2] A11!2 [D^7@2 C#m7 Bm7] [C#m7@2 F#m7@2] [D^7@2 C#m7 Bm7] [C#m7@2 F#m7@2] [D^7@2 C#m7 Bm7] [C#7@2 F#m7@2] A11!2>"],
  // chorus (8 bars)
  [8, "<[Bm7@2 E9@2] [C#m7@2 F#m7@2] [Bm7@2 E9@2] [A^9@2 F#m7@2] [Bm7@2 E9@2] [C#m7@2 F#m7@2] A9sus!2>"],
  // verse (16 bars)
  [16, "<[D^7@2 C#m7 A6] [C#m7@2 F#m11@2] [D^7@2 C#m7 A6] [C#m7@2 F#m11@2] [Bm7@2 E9@2] [C#m7@2 F#m7@2] A11!2 [D^7@2 C#m7 Bm7] [C#m7@2 F#m7@2] [D^7@2 C#m7 Bm7] [C#m7@2 F#m7@2] [D^7@2 C#m7 Bm7] [C#7@2 F#m7@2] A11!2>"],
  // chorus (8 bars)
  [8, "<[D^7@2 C#m7 Bm7] [C#m7@2 F#m7@2] [D^7@2 C#m7 Bm7] [C#m7@2 F#m7@2] [D^7@2 C#m7 Bm7] [C#7@2 F#m7@2] A11!2>"],
  // chorus (8 bars)
  [8, "<[Bm7@2 E9@2] [C#m7@2 F#m7@2] [Bm7@2 E9@2] [A^9@2 F#m7@2] [Bm7@2 E9@2] [C#m7@2 F#m7@2] A11!2>"],
  // chorus (8 bars)
  [8, "<[Bm7@2 E9@2] [C#m7@2 F#m7@2] [Bm7@2 E9@2] [A^9@2 F#m7@2] [Bm7@2 E9@2] [C#m7@2 F#m7@2] A11!2>"],
  // coda (2 bars)
  [2, "<B11!2>"],
)
const bassline = arrange(
  [10, "<[d2@2 c#2 a2] [c#2@2 f#2@2] [d2@2 c#2 a2] [c#2@2 f#2@2] [d2@2 c#2 a2] [c#2@2 f#2@2] a2!4>"],
  [16, "<[d2@2 c#2 a2] [c#2@2 f#2@2] [d2@2 c#2 a2] [c#2@2 f#2@2] [d2@2 c#2 a2] [c#2@2 f#2@2] a2!2 [d2@2 c#2 a2] [c#2@2 f#2@2] [d2@2 c#2 a2] [c#2@2 f#2@2] [d2@2 c#2 a2] [c#2@2 f#2@2] a2!2>"],
  [8, "<[b2@2 e2@2] [c#2@2 f#2@2] [b2@2 e2@2] [c#2@2 f#2@2] [b2@2 e2@2] [c#2@2 f#2@2] a2!2>"],
  [16, "<[d2@2 c#2 a2] [c#2@2 f#2@2] [d2@2 c#2 a2] [c#2@2 f#2@2] [b2@2 e2@2] [c#2@2 f#2@2] a2!2 [d2@2 c#2 a2] [c#2@2 f#2@2] [d2@2 c#2 a2] [c#2@2 f#2@2] [d2@2 c#2 a2] [c#2@2 f#2@2] a2!2>"],
  [8, "<[d2@2 c#2 a2] [c#2@2 f#2@2] [d2@2 c#2 a2] [c#2@2 f#2@2] [d2@2 c#2 a2] [c#2@2 f#2@2] a2!2>"],
  [8, "<[b2@2 e2@2] [c#2@2 f#2@2] [b2@2 e2@2] [c#2@2 f#2@2] [b2@2 e2@2] [c#2@2 f#2@2] a2!2>"],
  [8, "<[b2@2 e2@2] [c#2@2 f#2@2] [b2@2 e2@2] [c#2@2 f#2@2] [b2@2 e2@2] [c#2@2 f#2@2] a2!2>"],
  [2, "<b2!2>"],
)

// chords · gm_piano
const keys = chord(chords).voicing().s("gm_piano").gain(0.8)
// bass · gm_electric_bass_finger
const bass = note(bassline).s("gm_electric_bass_finger").gain(0.9)
// drums
const drums = s("[bd hh] [sd hh] [bd hh] [sd hh]").gain(0.8)

stack(keys, bass, drums)