The Monty Python gang use one to fizz up their TV sound track. Symphony orchestra members consider it the forgotten drainpipe of the wind section. And one writer compared its sinuous contours to an elephant's digestive tract, which, alas, is what it sounds like in the wrong hands. But to a gentle blue-eyed English historian named Christopher Monk, the serpent—as the curvaceous baroque instrument is called—is exquisite in looks and sound. "There's humor to serpents," Monk admits, "but I won't stand to see them treated as a joke."

Monk's passion for serpents is missionary. With two friends, he formed the London Serpent Trio and began transcribing works by Handel, Mendelssohn and Wagner to expand the instrument's meager repertoire. A favorite of cathedral choirs and royal orchestras all over Europe in the 17th and 18th centuries, the serpent produces a mellow sound not unlike the bassoon or tuba. The London threesome have supplied it for the sound tracks of such movies as Journey to the Center of the Earth and The Devils and for several TV shows.

Monk, a retired schoolteacher, and his small staff build some 50 serpents a year in a Surrey workshop. They're made of sycamore or walnut and sheathed in leather. The price is $525, and there is always a waiting list.

Why would anyone wish to conquer such a musical beast? Monk, 57, says his ultimate joy is making the serpent sing. "It's like driving a vintage car," he says, hoisting his own 1810 French instrument. "You have to work at it but the pleasure is too beautiful for words."