Some 25 years of teaching have taught me that we players must always define what each of our motions at the cello represents - this is essential in order for us to be efficient artists capable of technical ease, great stamina, physical power and musical depth. To have control I must develop the ability to use my physical gestures economically and unconsciously. Craftsmanship - the non-musical aspect of playing, such as finger velocity, bowing technique, shifting and so on - should be studied separately from musical expression. Expressive possibilities are limited if the player is not at home with the instrument, and the further one goes away from 'home' the more the basics are needed.

This is why I believe in etudes and studies - and I still play scales - as Heifetz emphasised. I don't find this technical work pleasurable, but I do it anyway. A wonderful part of instrumental fitness can be found in exercises by Feuillard and Cossman for example..

Not all instrumentalists regard exercises as important; in fact, many artists think etudes are rubbish and that one can learn technique through pieces. I say yes, if you understand what you have to do. An etude is like a series of small limited structures and should be played with complete control without the emotional distractions of your concerto. If you apply that behaviour to your solo and find the pattern you need to work on, you can practise the passage with the same sensibility that you would an etude. At this point all enemies of this approach will say, 'Now the concerto will sound like an etude!' They are right. Anyone can describe what to do, but it takes knowledge of the basics to approach the problem. That's why I work on etudes.

Consider other musicians. All singers certainly begin the day with basic vocal exercises: arpeggios, scales, exercises for tone and for intonation. They practise their routine in every key, making sure their voices are properly supported. Wind players hold long notes for endurance and breath control. We string players don't do this enough - especially young players, who should be trying to find their own voice. I suggest starting on the open strings with or without vibrato. I concentrate on the physical aspects of playing. I question myself. Is my body comfortable? Can I control the bow in fast and slow speeds? How should I vary my vibrato? I keep the note plain then add vibrato as a sheer physical exercise. If it sounds 'dry', I don't do it. Even when the gesture is detached from the artistic act you must love the note, feel yourself relax, enjoy your instrument and get addicted to the sound you produce in order to be able always to find a home; otherwise, when the music makes increasingly difficult demands, you could lose control. The more aware I am of my physical approach, the easier artistic matters become.

A tactic I often use in masterclasses is to ask the student to play something quiet and small, like a simple row of notes at a moderato tempo. Then we increase the dynamics to mezzoforte or forte, playing full but not too loud. Perhaps we choose a few notes from the concerto, maybe with a slide because it makes us nervous.

Sometimes I ask for a Š evÄík or Feuillard exercise - we are looking for something simple in order to come back to basics.

Basics include posture. When sitting at the instrument the torso must lean towards the cello. You must find a position in which you can sit for many hours. I control my neck, avoiding pushing away or pressing towards the cello, which causes tension. If I am relaxed from the hips, my torso can help my arms produce the weight. Tension in the hips reduces power. Likewise, lifting the shoulders (a mistake we all make) interrupts the flow of energy into the fingers by creating stress. This applies to both arms.

Concerning power - and cellists need a lot - one can be lucky or one must train for endurance. Producing sound from force is wrong. You must be strong, but use body weight and gravity. Besides, we would have to develop more muscles than needed in order to have reserve strength, since we should be able to play through three concertos in the practice room in order to perform one. In the same way, I have to master passages that are more difficult than the works I play on stage. So, I go back to etudes in order to make the Dvorák Concerto easier. You have to be fitter than required and you have to have more skill than needed.

Developing the artistic ingredients and controlling emotions are difficult. We have players who are well educated but lack imagination. Musicianship is, of course, as important to prepare as the craftsmanship aspect. Generally I find artistic information about composers has to do with performance practice. How did Beethoven's violin sonatas sound? There is a lot of information available and I think it is important to find that information, but it takes time and energy.

Emotionally, though, I think the cellist has to try to develop colours and atmospheres with the pressure and speed of the bow, vibrato and expressive shifting, and find a repertoire of possibilities that are called personal, but are connected to the instrument. In order to enrich the palette of human experience available to me I go to the theatre, exhibitions, opera and ballet, as well as experiencing non-musical culture. I read. I learn as much as possible about psychology, for example, in order to nourish myself as a person and to become more knowledgeable. György Ligeti speaks about finding inspiration from scientists; their research makes him able to be creative as a composer. I find listening to records is not enough to enable you to become an interesting artist. It's fascinating, yes, and shouldn't be missed. But engage your mind more widely. Ask questions that will make you a richer person.

As an end result, I adapt my ability to apply the etudes I practised to the Elgar Concerto. In the performance I repeat my exercises of relaxation and subtlety. I bring together the elements of vibrato and bow control with those of expression and, I hope, land at Elgar. These are the rules I follow: Play scales to the end of your life! Practise slowly. Don't play loud and fast. Control your body. Think like a singer and feel the breath from your stomach. And finally, be patient and don't give up.

This article was first published in The Strad's December 2004 issue.