The answer is ... blowing in the wind section

OBSCURE INSTRUMENTS OF THE ORCHESTRA.

A continuation by Dr Arnold Weiskopf of his occasional survey of the less well-known corners of the symphony orchestra.

75. The Clavicorn.

A brave but doomed attempt to combine the pianoforte family and the reed family, this is not unlike a very large clarinet with a keyboard. "A piano that may be blown through will have the ultimate advantage of portability," said the inventor, Zwemmling, in 1820. What he hadn't realised was that unless you only played one note at a time, it would take three or four people blowing it simultaneously to get a noise out of it. If clavicorn pieces are ever played these days, the part is usually taken by a dozen clarinettists.

76. The Violello.

The violello is the very little-known member of the string family that comes between the viola and the cello. "The cello and the double bass rest on the floor," said Kirschner, "and the violin and the viola rest on the shoulder. It surely stands to reason that there must be an intermediate instrument which is played on the lap or between the knees." This was the violello, which produced a most beautiful tone somewhat like, in Bernard Shaw's words, "an Irish tenor performing to an all-female audience". It died out in the 1900s, and all the jokes hitherto told about violello players were henceforth told about viola and banjo players.

77. The Saxulele.

Adolph Sax invented many instruments, some of which have become obsolete with time. Only the saxulele, however, lies at the bottom of the Atlantic ocean. The Belgian inventor was fascinated by the sound of the loud, ringing, plucked instruments favoured by black Americans - the banjo etc - and with his usual restless mind devised a combination of the banjo and saxophone, which could be heard three miles away on a clear night. He shipped a cargo of these redoubtable instruments over to America for experimental sale but the ship went down in a fierce storm off the Florida Keys, taking with it all the known examples of the saxulele. Legend has it that on stormy nights off the Florida coast you can hear a ghostly band of saxuleles playing, "Stormy Weather" in G, which seems unlikely, as the song was not written till 100 years after the shipwreck.

78. Opera Obscura.

Not strictly speaking a musical instrument, but a device which in its day had some fame and should perhaps

be brought back. It catered for those unfortunates who were sensitive enough to enjoy the sight of the opera but not the sound. It was discovered that if you made a small hole in the back of an opera house, the image of the performance within could be transmitted on to a screen in a room at the back, in the manner of a "camera obscura". This meant that those who wished to enjoy the spectacle but be spared the warbling could sit behind the opera house and watch everything that happened on stage, albeit upside down.

Incidentally, we have had a couple of letters from classical music lovers with genuine queries which Dr Arnold Weiskopf is happy to answer.

Dear Dr Weiskopf,

There is a reference to a basset-horn in Jilly Cooper's latest interesting work about the orchestra, Appassionata. What kind of instrument is this?

Dr Arnold Weiskopf writes:

There is indeed a genuine kind of wind instrument called a basset-horn, but in this novel it seems to refer to a kind of veterinary device used to give dogs an enema. Miss Cooper is, as you know, a lover of dogs and she seems to have been misled by the existence of a breed of dog known as a basset hound into thinking ... well, into thinking something or other.

Dear Dr Weiskopf,

The famous percussionist Evelyn Glennie is always described as being "profoundly deaf", yet in interviews she seems to hear everything that is said and to talk normally. How can this be?

Dr Arnold Weiskopf writes:

Like many musicians, Miss Glennie often sends in a "dep" to do her more wearisome gigs for her. In her case, this certainly covers her radio interviews and TV trips, so we can be sure that when we hear her speaking, it is not her but someone Scottish who hears and speaks perfectly normally.

However, I am sure that she fulfils all her musical engagements in person, as it is not particularly necessary for an orchestral player to hear what your colleagues are doing, and can often be a disadvantage.