Boomwhackers are coloured plastic tubes that each produce a single note. You strike them against your hand, your knee or the floor, and that is more or less the whole technique. The challenge sits exactly there: you hold only one or two notes, so the piece exists only if everyone comes in at the right moment. Listening, watching each other and arriving exactly on time matter from the first minute.
What starts as scattered knocking turns surprisingly quickly into something that sounds like music. No experience is required, only the willingness to build something together, and the first time it lands the whole room hears it at once. Anyone can keep up, from musicians to people who have never held an instrument.