A Lindenmayer system grows a string by rewriting it with the same rules,
over and over — the grammar botanists use to model plants. This page reads the grown string
twice: as turtle graphics (the plant you see) and as music —
F plays a note, +/− step up/down the scale,
and […] branches rewind time, so every twig becomes a simultaneous
voice, quieter with depth. The phrase is self-similar: iteration four contains iteration
three, everywhere, transposed. Edit the rules and replay your own species.