Only a handful of professional musicians can play it, but a rare instrument banned in the 19th century is making a comeback, and even seducing rock and electro stars.
The glass armonica, invented by US founding father Benjamin Franklin in the 18th century, was blamed for driving musicians crazy, and is not taught in any of the world's top conservatories.
"There are five or six of us who play it, for our own pleasure. It's a very small community," says Frenchman Thomas Bloch, one of the exclusive musical club.
But now Bloch has been invited by the Los Angeles Opera to play the instrument - which he jokingly says looks like a rotating glass kebab - in the Donizetti opera Lucia di Lammermoor, which runs until April 6.
The spelling, without an "h," was ordained by Franklin himself, even if some have tweaked it to harmonica. It is based on the Italian word "armonia", meaning harmony, evoking the instrument's harmonic richness.
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It is, in fact, a sophisticated version of an "instrument" that everyone knows: a glass filled with water, which produces a high-pitched ringing sound when a moistened finger is drawn around its lip.
Franklin got the idea after seeing musicians in London "playing" rows of glasses that were filled with water to varying levels to make different notes. But he wanted a more easily transportable version.
"So he asked a glass blower to create 37 bowls of different sizes, tuned chromatically over three octaves," Bloch says.
The bowls are fitted inside each other without touching and fixed on a rotating horizontal axle, the speed of which can be controlled by a pedal.
The player makes music by sliding fingers across them, moistened with a mix of water and chalk.
The whole thing looks a bit like a mixture of "a sewing machine and a translucent kebab", Bloch says.
The instrument was an instant hit and France's Queen Marie-Antoinette herself played it.
"There are believed to have been about 4000 armonicas built between 1761 and 1835. It was played in salons above all," says Bloch.
Mozart liked the glass armonica so much he used it for his final chamber music work.
Beethoven, Carl Philipp Emanuel Bach, Saint-Saens, and later on Richard Strauss, also composed music for the instrument, which was nicknamed "the angels' organ" by Paganini.
But the instrument's success was not without controversy.
Critics said its ethereal sound provoked premature births, made animals roar and felled "the strongest man in less than an hour," according to an 1804 medical dictionary. Above all, it allegedly made its players go crazy.
"At first they thought it was due to its rich harmonics," says Bloch. "But the real problem was the lead."
In the 18th century armonicas were made of crystal, composed of 24 per cent lead. And the black paint applied to some of the bowls - resembling the black keys on a piano keyboard - were also full of the toxic metal.
"Touching these instruments every day for 15 or 20 years could be a real problem, specifically with lead poisoning," he says.
In 1835, German police banned the glass armonica.
The instrument was gradually forgotten - until a German-born master glass blower living near Boston, Gerhard Finkenbeiner, started making them again in 1982. His workshop remains the only manufacturer of the instrument, which costs some 15,000 (about $A22,414).
Its resurrection was accompanied by a revival of music for it - some 400 pieces exist, including Lucia di Lammermoor, in which the armonica had been replaced by flutes.
It was Bloch who oversaw the "re-creation" of the opera in its original version in the 1980s.
But the instrument's sounds have also drawn a new generation of musicians, including Icelandic songstress Bjork and avant-garde composer John Cage. It was also used in the 1975 hit film One Flew Over The Cuckoo's Nest.
"Clearly if it was taught formally it would allow the instrument to be more widely known," says Bloch.
But the musician has already been spreading the word, having worked with Radiohead and Tom Waits, as well as electro stars Gorillaz and Daft Punk.
