This has happened before may be played live by four clarinettists, all playing clarinets of the same size, or recorded by one multitracked clarinettist. All four clarinettists play the same melodic sequence, the second, third and fourth players entering at the points indicated and playing slightly faster than the first player, the intention being that all four performances of the melodic sequence should finish at roughly the same time.

Duration is flexible. White notes are relatively long, black notes rather shorter. Commas indicate the taking of a quick breath. The score is more evenly spaced than any performance should be. If the white notes are about four seconds long then the overall duration should be about ten minutes.

This has happened before was written in July and August 2020 for Ronald Woodley.