mary-had-a-little-lamb.fsx

type Tone =
    | Rest = 0
    | GbelowC = 196
    | A = 220
    | Asharp = 233
    | B = 247
    | C = 262
    | Csharp = 277
    | D = 294
    | E = 330
    | F = 349
    | Fsharp = 370
    | G = 392
    | Gsharp = 415

type Duration =
    | Whole = 1600
    | Half = 800
    | Quarter = 400
    | Eigth = 200
    | Sixteenth = 100

type Note = Tone * Duration

let play (tune: seq<Note>) =
    for tone, duration in tune do
        match tone with
        | Tone.Rest -> System.Threading.Thread.Sleep(int duration)
        | _ -> System.Console.Beep(int tone, int duration)

let tune = [
    Tone.B, Duration.Quarter
    Tone.A, Duration.Quarter
    Tone.GbelowC, Duration.Quarter
    Tone.A, Duration.Quarter
    Tone.B, Duration.Quarter
    Tone.B, Duration.Quarter
    Tone.B, Duration.Half
    Tone.A, Duration.Quarter
    Tone.A, Duration.Quarter
    Tone.A, Duration.Half
    Tone.B, Duration.Quarter
    Tone.D, Duration.Quarter
    Tone.D, Duration.Half
]

play tune