Provided you connect a piezo speaker to your Arduino board, the tone Arduino function allows to play tones given their frequencies. Let's use it to play entire melodies!

The Arduino board of my robotic teapot with a piezo sounder

The melody encoding format I'll use is compact and pretty straightforward, but I admit it isn't the easiest one to read. The melody is represented as a null-terminated string of chars, in which each note is described by 3 consecutive characters:

1. The note duration in sixteenth notes as an hexadecimal digit between 0 and F (0 has a special meaning and is interpreted as a whole note)
2. The note name in English notation as an uppercase letter, or lowercase if sharp (R has a special meaning and indicates a rest)
3. The octave number as a decimal digit, between 0 and 8 (for a rest, the value is ignored)

So for instance, a quarter-note C from the 5th octave is 4C5, and a eighth-note D sharp from the 4th octave is 2d4.

With this notation, the Tetris theme is:

4E52B42C54D52C52B44A42A42C54E52D52C56B42C54D54E54C54A42A42A42B42C56D52F54A52G52F56E52C54E52D52C54B42B42C54D54E54C54A44A44R0

In this example, a piezo passive sounder is connected on pin 3 …