Actually a set of four or five separate drums with overlapping ranges. each drum is tuned by foot pedal. retuning a drum to a different note cannot be done instantaneously although you can change notes in the middle of a com-position you should allow several measures rest for the timpanist to do this for beginners it might be best to set a group of four notes one for each drum at the beginning of a piece and not change them extended notes are accomplished via a two-handed roll