Hyperbass flute

The hyperbass flute is conceptually the largest and lowest-pitched instrument in the flute family, although it is extremely rare. It first appeared at the turn of the 21st century, and only two are known to exist. With tubing reaching over 8 metres (26 ft) in length, it is pitched in C, four octaves below the concert flute (three octaves below the bass, two below the contrabass, and one octave below the double contrabass). Its lowest note is C₀, one octave below the lowest C on a standard piano, which at 16 hertz is considered at or below the threshold of human hearing.

The first playable example was built by Florentine craftsman Francesco Romei for Italian flutist Roberto Fabbriciani, inventor and first performer of the instrument. He called it the hyperbass flute (Italian: flauto iperbasso). This first instrument was made from PVC and wood, with wide tone holes made from standard tee fittings, but without keys; these are covered with the palms of the hands. Low flute specialist Peter Sheridan commissioned the first fully chromatic hyperbass flute, from the Dutch maker Jelle Hogenhuis in August 2010.