When my son wrote to Father Christmas last year asking, out of the blue, for a violin, I was pleased, but also placed in a quandary. He seemed, at four-and-a-half, temperamentally unready for the rigours of daily practice that would be required to get him launched on a difficult instrument. But on the other hand, as an unprompted expression of musical interest, shouldn't I be taking his request more seriously and doing what I could to encourage him?
I decided, feeling rather mean, to put it off for another year at least, and made a feeble excuse to my son on Father Christmas's behalf. But the questions remain: how should you go about choosing an instrument for your child, when are they ready to start, and how far do you let them make the choice for themselves?
One father, who asked his son, now grown-up, what instrument he wanted to play and agreed to trumpet lessons, is now of the opinion that too much family democracy was a mistake. "He couldn't get the puff and so it was a disaster. He went right off the idea of playing any instrument at all. But if we'd said, `It's the piano for you, my boy,' he would probably have really enjoyed it."
Atarah Ben-Tovim, a former teenage prodigy on the flute who has done extensive research into matching children with instruments, is convinced that "choosing the wrong instrument is the most common factor in musical failure, not lack of musicality or musical potential".
Her book, The Right Instrument For Your Child, co-written with her husband, Douglas Boyd, and now in its third edition (Gollancz, pounds 6.99), sets out a step-by-step system to help parents select an instrument. Children must first pass Ben-Tovim's simple "musicality" test, and a "readiness" test, which requires them to be coping well at school, reading and writing comfortably and with mental energy to spare, before they begin on an instrument. Parents then fill in a "three-way profile", an assessment on their child's physical, mental and personal attributes, according to which different instruments are deemed suitable or not.
A flute, for instance, Ben-Tovim asserts, "would not suit an aggressive or dominant child," whereas a trumpet is ideal for "the prima donna temperament" - a child who wants to dominate the sound of the group and has "the kind of short-burst energy which makes a football or netball centre-forward".
Reading and playing piano music "requires a brain good at mental arithmetic," Ben-Tovim says, and the true pianist is "a natural loner who likes privacy ... and has an instinctive desire to be self-sufficient".
Percussion can do wonders for the "hyperactive" child. Strings require a "very high degree of conscientiousness" and suit "quietly behaved children" - not my son, then? - the sort who are "quite happy reading in the bedroom or playing with one or two close friends".
While such an approach has obviously proved useful to many parents, there is perhaps a danger that it is over-schematic, typecasting children and paying too little attention to their own musical feelings. "One of the key things in learning to play an instrument must be the motivation of the youngster to learn that particular instrument," says John Stephens, head of music education at Trinity College of Music in London.
Cathy (not her real name), now a professional oboist and teacher, as a child began on the violin, because there was a teacher available at school and because her father had played the violin.
"But I loathed it. I didn't have the right co-ordination, I didn't like the way you played it sideways, I didn't like the way you heard it in one ear. I didn't fall in love with the sound."
She switched, in her early teens, to the oboe, and immediately knew she had found the "right" instrument. "I loved the sound it made, and I didn't find it difficult. I was completely hooked."
Faith Whiteley, who runs a Saturday morning string course for children aged five to 10 at the Guildhall School in London, agrees that to succeed on an instrument a child needs to have "the desire to make that sound". Taking young children to an orchestral concert is an ideal way of introducing them to the sounds of different instruments - rather than simply visiting a music shop, where they will not hear the instruments played properly. If a child is particularly fired by a sound, she advises, go for that sound regardless; good teaching can generally overcome any physical or other difficulties with the instrument.
Children with no obvious passions can be guided towards an instrument that they are physically adapted to; for instance, a very small child will not find the cello easy, while large hands suit cellos and basses better than violins. Teeth formation or the wearing of a brace can occasionally cause problems for a wind player, so advice should be sought from a teacher.
Don't assume that the piano is necessarily the right instrument for all children to start on just because piano teachers tend to be more plentiful. While some children clearly find the piano very satisfying, because you are playing all the parts, others will feel more confident with a single-note instrument to begin with - and they can always take up the piano later on.
A good teacher is essential, and, these days, costs money. Faith Whiteley has set up a charity, Children in Music Education, to help subsidise those who cannot afford lessons. But more local authorities now offer "kinder music" for children aged four to seven, classes encompassing a wide range of musical activities from singing and playing to making up tunes. And these provide an excellent foundation for learning an instrument, as well as being considerably cheaper than individual lessons.
Whichever instrument you and your child choose between you, most important is that the child has your support and encouragement, and acquires the habit of regular, daily practice (10 minutes a day is quite enough to start with).
"Children are very nervous when they start out on an instrument, and some parents can't give praise because the child never seems quite good enough," says Faith. "But children must be allowed to progress at their own pace.
"Parents must be delighted by what their child is doing, and keep telling them how much pleasure the music is giving them."
striking the right note
l Flute: suits shy or lonely children, and the quietly sociable.
l Oboe: determined, stubborn children do best.
l Clarinet: enjoyed by quick learners and impatient children, who are also bright, alert and sociable.
l Trumpet: suits children with a prima donna temperament, energy and a desire to dominate the sound of the group.
l Violin: demands intelligence, sensitivity and extreme conscientiousness; not for the boisterous.
l Cello: suits a quiet and reflective intelligence; not for children of small or below-average build.
l Piano: the true pianist may be shy or an exhibitionist, but with an instinctive desire to be self-sufficient; also needs to be good at mental arithmetic.