Slightly off-topic, but regarding unusual insrtuments:
We have all heard of the Bass Flute, Contra-Alto & Contrabass Flute, but I am amazed to discover a Sub-Contrabass Flute and a Hyperbass Flute, and there has been music written for all of them.
The Hyperbass Flute is not an instrument one would tuck under an arm while running for a bus. It is over 8m in length, (tubing conveniently layered), pitched in C, its lowest note (Co) is 4 octaves below the lowest C on the standard Flute, and an octave below the lowest C on the Piano (C1).
Player Roberto Fabbriciani has already recorded a piece "Con Fuoco" by composer Nicolas Sani. I doubt if most of us could actually hear a note so low, and I really wonder what purpose they serve. I suppose it relates to pushing the boundries. Very low notes on such instruments would be indistinct and "muddy" anyway, but Sylvio Lazzari (1857-1944), makes good use of them on conventional instruments,(Bass Clarinet & Contrabassoon), to create the atmosphere (at the beginning),in one of the great French unsung Symphonic Poems, "Effet de Nuit", and Wagner needs no mention.
I have seen a photo of an Octo-Bass (Dble Bass), standing 3.5metres in height, which was either made, and, or, played in Paris in the mid 19th century,(1849 ?) but as far as I know it has remained in the museum.
Marcus.