The tenor or “lead” pan is the highest and most prominent melody voice in a pan ensemble. Anthony Williams designed the "fourths and fifths" arrangement of notes, known as the cycle of fifths, starting with the lowest C closest to the player. This has become the standard form of note placement for lead pans. The most common pan used in an ensemble, the lead is often the most numerous in a large steel band. Often misnamed a steel drum because it is struck with implements and is fabricated from a 55-gallon oil drum, the pan is not a membranophone. The pan is an idiophone, with the tenor voice sounding chromatic pitches from a single instrument. The rubber-tipped aluminum stick beaters are lightweight to protect against striking the strike bosses out of tune during aggressive play.