func GenerateBassMelody() (notes chan music.Note) {
notes = make(chan music.Note)
go func() {
for {
var octave int
x := rand.Float64()
if x < 0.3 {
octave = 3
} else {
octave = 2
}
root := music.MakeNote(music.D, octave)
scale := music.Scale{Root: root, Intervals: music.HarmonicMinor}
var n int
x = rand.Float64()
if x < 0.2 {
n = 3
} else if x < 0.4 {
n = 6
} else if x < 0.6 {
n = 9
} else if x < 0.8 {
n = 12
} else {
n = 18
}
for i := 0; i < n; i++ {
notes <- scale.Root
NextNote(&scale, root)
}
}
}()
return notes
}
// A simple C major scale played on a sine oscillator.
// A single call to 'Sine' is used, with its frequency modulated through each of
// the notes.
package main
import (
"github.com/kierdavis/gosound/frontend"
"github.com/kierdavis/gosound/music"
"github.com/kierdavis/gosound/sound"
"time"
)
var Notes = []music.Note{
music.MakeNote(music.C, 4),
music.MakeNote(music.D, 4),
music.MakeNote(music.E, 4),
music.MakeNote(music.F, 4),
music.MakeNote(music.G, 4),
music.MakeNote(music.A, 4),
music.MakeNote(music.B, 4),
music.MakeNote(music.C, 5),
// The last note is duplicated so that the frequency envelope will extend
// longer than necessary. This is to ensure that the oscillator continues
// playing once 8*NoteDuration has elapsed, so that we can find a zero
// crossing to stop at.
music.MakeNote(music.C, 5),
}
const NoteDuration = (time.Second * 3) / 10
func Generate(ctx sound.Context) (left, right chan float64) {
rand.Seed(time.Now().UnixNano())
melodyParts := make(chan chan float64)
bassParts := make(chan chan float64)
go func() {
for {
var octave int
x := rand.Float64()
if x < 0.3 {
octave = 4
} else {
octave = 5
}
root := music.MakeNote(music.D, octave)
scale := music.Scale{Root: root, Intervals: music.HarmonicMinor}
var n int
x = rand.Float64()
if x < 0.2 {
n = 3
} else if x < 0.4 {
n = 6
} else if x < 0.6 {
n = 12
} else if x < 0.8 {
n = 18
} else {
n = 24
}
melodyParts <- genMelodyArpeggio(ctx, scale, n)
}
}()
go func() {
for {
var octave int
x := rand.Float64()
if x < 0.3 {
octave = 3
} else {
octave = 2
}
root := music.MakeNote(music.D, octave)
scale := music.Scale{Root: root, Intervals: music.HarmonicMinor}
var n int
x = rand.Float64()
if x < 0.2 {
n = 3
} else if x < 0.4 {
n = 6
} else if x < 0.6 {
n = 9
} else if x < 0.8 {
n = 12
} else {
n = 18
}
bassParts <- genBassArpeggio(ctx, scale, n)
}
}()
melody := playMelodySynth(ctx, ctx.AppendStream(melodyParts))
bass := playBassSynth(ctx, ctx.AppendStream(bassParts))
melodyLeft, melodyRight := ctx.Fork2(melody)
bassLeft, bassRight := ctx.Fork2(bass)
left = ctx.TakeDuration(
ctx.Add(
ctx.Mul(melodyLeft, ctx.Const(0.4)),
ctx.Mul(bassLeft, ctx.Const(0.6)),
),
time.Second*300,
true,
)
right = ctx.TakeDuration(
ctx.Add(
ctx.Mul(melodyRight, ctx.Const(0.6)),
ctx.Mul(bassRight, ctx.Const(0.4)),
),
time.Second*300,
true,
)
return left, right
}