The pieces make heavy use of extended techniques, including playing with the back end of the timpani sticks, varying the beating spot on the drumhead, glissandos, and sympathetic vibration.
It is played with thin rattan shafts with moleskin on the ends rather than conventional timpani sticks.
"Adagio", composed in 1966, is written for pedal timpani, and explores the many effects possible by changing the pitch of the drum while playing.
"Recitative" is a dramatic, slow piece that consists of three different elements: a tremolo, a bolero rhythm, and an irregular pulse.
"Canto", added in 1966, is played with snare drum sticks, and uses pedal timpani to imply a continuous melodic line.