Supporting a column of air

You must really feel you have arrived as a musician when you no longer have to worry about the neighbours complaining about the noise. Not only because: a) you're no longer making noise, you're making music, but also: b) you've got your own studio to practise in, rather than your spare room.

Clarinettist Emma Johnson, who will be playing at the National Concert Hall next week, lives in London's Greenwich. "We managed to find this incredible house with a studio in the garden," she explains down the phone from London. "The neighbours told us it used to be a chocolate factory in the last century." The house is early 18th-century, and the building at the bottom of the garden, which once was filled with the smell of cocoa, is now home to a 20-piece chamber group and a Steinway grand piano.

Johnson, who was born in London, started playing the clarinet when she was nine. Her parents had given her a recorder when she was a small child. "I played it so much I drove them mad," she admits cheerfully. "And it's quite a squeaky sound."

When she was nine, the school Johnson attended was offering a free term's tuition in violin, clarinet or trumpet to all pupils. She chose clarinet, since she'd already been playing the recorder, and it was "another blowing instrument". Her father collected jazz records, and Johnson had grown up listening to them.

"The clarinet sounds a lot like the human voice," she explains. "I love the physical sensation of playing my clarinet. It's like singing - you're supporting a column of air, using breath control. I love the sound of the contrast between the dark low register and the more flute-like upper register."

Does she think she would have had a similarly successful career if she had chosen a different instrument - would the music in her have emerged regardless? She thinks down the phone for a while. "I think I always would have been a musician. Playing the violin professionally would have been harder, because you need so much specialist training. The fact that I was playing the clarinet meant that I was able to keep attending an ordinary school, by practising very hard in the evenings."

She plays an instrument which was made by the only English clarinet maker, Peter Easton. "Most clarinets these days are made in France or Japan, and made in bulk. Peter's instruments are made by hand and to order. His instruments are more lyrical than others. You can get a bigger range of expression out of them."

Unlike some musical instruments, such as violins, which season with age and use, clarinets wear out. To have an old one is no advantage at all, which is probably why they are mass-produced. "You're doing a lot of pressing and touching the instrument," Johnson explains. "They do get worn out." The instrument she has at present is five years old. "It takes about five to ten years for the wood to mature, so it's just about right now."

Not many clarinet players make a career as a soloist: most stay within the orchestra. In 1984, she won the BBC Young Musician of the Year Award. The famous conductor, Yehudi Menuhin, took an interest and gave her a number of concerts when she was still a teenager. "He was very charming to me, and gave me very good advice and encouragement."

At 18, she was signed by ASV, and she has since recorded some 16 CDs with them, including concertos by Mozart, Rossini, Debussy, and Weber. In between recording, she has performed and toured extensively with orchestras such as the Royal Philharmonic, the English Chamber, the New Japan and Polish Chamber.

She has also formed her own chamber group. "You don't need so many people as you would for a full orchestra." They rehearse in the old chocolate factory, and have just finished a series of concerts, including the prestigious venues of the Wigmore Hall and Aldeburgh. In addition to her performances as a musician, she is also in demand as a conductor.

So is it all practice, practice, practice? "Sometimes I practise all day long, if I'm learning a new piece," she says. "Yesterday I did nothing - I was trying to do my accounts. The house is full of bits of paper, it's a sea of receipts. When you embark on a career in music, you don't realise you also have to be an accountant!"

What is the difference she hears now in pieces she first played several years previously? "You can bring a great knowledge to the piece. There's a bigger range of expression. When I listen to early recordings, they seem very fresh to me. I think time brings more insight and understanding to the music. But you still always feel you could get it better!"

This year, she'll spend six weeks touring the US, and several more weeks in France and Switzerland, as well as the usual tour of Britain. "About 75 concerts a year." So are there favourite pieces she has which she plays in concert?

"You love every piece you play," is the reply. "Otherwise you shouldn't be playing it in front of an audience." At the time of the interview, she was working on the repertoire for her Dublin concert, when she will be performing with pianist John Lenehan. "I know I'm going to play Brahms Sonata in E Flat in the middle of the concert. It's a beautiful romantic piece, full of love."

Emma Johnson plays clarinet and John Lenehan plays piano at the National Concert Hall on Thursday at 8 p.m. Bookings: 01-4170000.