The work is a parody of the classical double concerto but where one instrument, the hardart, uses different devices, such as plucked strings, blown whistles and popped balloons, to produce each note in its range.
Like the automat, the hardart had small windows in the front where the musician had to insert coins to remove implements needed to strike or otherwise play the devices that produced the notes.
The composer Philip Glass, a classmate of Schickele's,[1] helped build the actual instrument; Glass and the others tasked with building the hardart made it a transposing instrument without telling Schickele,[2] who had to transpose at sight during the performance.
[3] As with other works that Schickele attributed to P. D. Q. Bach, "beneath the satire one finds very sound technique and invention in the music.
A portion of the cadenza was sampled by the group Jurassic 5 in the song "Monkey Bars" on their album Quality Control.