# Teenage Mutant Ninja Turtles (1987 theme / NES title screen)
# for one RouterOS beeper --- https://lab.glossema.dev/play/turtles

# --- Tuning: equal temperament, integer Hz -----------------------------------
:global notes {
    "D3"=147; "F3"=175; "G3"=196; "Ab3"=208; "A3"=220;
    "C4"=262; "D4"=294; "F4"=349; "A4"=440;
    "C5"=523; "D5"=587; "F5"=698; "A5"=880
};

# --- Clock: 150 bpm, so the beat is 400ms and the riff runs in 200ms eighths --
:local beat 400ms;
:global durs {
    "s"=($beat / 4); "e"=($beat / 2); "q"=$beat;
    "h"=($beat * 2); "w"=($beat * 4)
};
:global gap 20ms;

# --- One voice: sound a note, then hold the clock so the notes articulate -----
:global play do={
    :global notes;
    :global durs;
    :global gap;
    :local d ($durs->$2);
    :if ($1 = "-") do={
        :delay ($d + $gap);
    } else={
        :local f ($notes->$1);
        :beep frequency=$f length=$d;
        :delay ($d + $gap);
    }
}

# --- Walk a melody written as "NOTE:dur" strings ------------------------------
:global phrase do={
    :global play;
    :foreach n in=$1 do={
        :local c [:find $n ":"];
        :local note [:pick $n 0 $c];
        :local dur [:pick $n ($c + 1) [:len $n]];
        $play $note $dur;
    }
}

# --- Part 1: the riff, even eighths, third and fourth octaves -----------------
:local riff {
    "D3:e"; "D3:e"; "F3:e"; "G3:e"; "D3:e"; "D3:e"; "G3:e"; "F3:e";
    "D3:e"; "D3:e"; "F3:e"; "G3:e"; "Ab3:e"; "A3:e"; "C4:e"; "D4:e"
};

# --- Part 2: the chant, set into the riff's gaps ------------------------------
# A low bass note lands on the strong beat wherever the voice rests.
:local chant {
    "D3:e";  "A4:e"; "A4:e"; "A4:e"; "A4:e"; "A4:e"; "A4:e"; "C5:e";
    "D5:q";  "-:q";  "D3:e"; "F3:e"; "G3:e"; "A3:e";
    "D3:e";  "A4:e"; "A4:e"; "A4:e"; "A4:e"; "A4:e"; "A4:e"; "C5:e";
    "D5:q";  "-:q";  "D3:e"; "F3:e"; "G3:e"; "Ab3:e";
    "D3:e";  "D5:e"; "D5:e"; "C5:e"; "C5:e"; "A4:e"; "A4:q";
    "D3:e";  "F3:e"; "G3:e"; "A3:e"; "D3:e"; "D3:e"; "F3:e"; "G3:e"
};

# --- Part 3: "turtle power" --- the answering cadence and the shout -----------
:local power {
    "D3:e";  "A4:e"; "A4:e"; "C5:e"; "D5:h";
    "D3:e";  "F3:e"; "G3:e"; "Ab3:e";
    "A3:e";  "C5:e"; "D5:e"; "F5:e";
    "A5:w";
    "-:q";   "D3:q"; "D5:w"
};

# --- Performance --------------------------------------------------------------
:put "Riff";
:for i from=1 to=2 do={ $phrase $riff; }

:put "Chant";
$phrase $chant;
$phrase $riff;
$phrase $chant;

:put "Turtle power";
$phrase $power;