Improvisation has been in my blood since I started to learn the piano at the age of eight. I had a gift for hearing music, then being able to sit at the piano and laboriously pick out what I had heard. If I saw a film I liked, I raced home to pick out the theme on the piano. I learned to play the piano well as an improviser long before I could master the disciplines of sight reading and technical prowess. Of course at the time (the early 1970s), improvisation was dismissed as 'playing around', particularly by my then piano teacher, and although it was great therapy for me, I didn't envisage earning my living with it.

To have fallen into a career that required long spells of continuously creative improvisation was luck, not planning. But silent film accompaniment is, to me, composition on the hoof. As a scene unfolds I try to judge mood, environment, the shift in control of a scene from one character to another, the turning points that need to be marked. It helps that I studied drama, not music, at university, as all film, TV and game composers are dramaturges at heart.

I try to play a scene from the inside outwards, trying to feel the characters pathways and translate them into music. I suppose I must have a beat clicking in my head (particularly with fast-moving scenes) but often I am feeling for the next chord, deciding whether to resolve the musical phrase or use it to fire off another phrase. Melody, being linear, has to have space to make an impact, whereas chord changes are immediate and can make or break a mood instantly. And there is always material to work with, no matter how boring the film; in a scene in which two people are facing off in a hut in the tropics, the heat, the tension, the slowness of body movements, the editing, as well as the scene itself will all feed into the music.

The music feels familiar without being recognisable, and that's where I would take issue with the pejorative term cliché. We audiences are hugely sophisticated receptors for film music, and pushing those intuitive buttons (without seeming to) is what film composers should be aiming for. Cliché cheapens a scene - intuitive creativity makes the scene inclusive and resonant. As long as the music is truthful to the subtext of a scene, it will not be clichéd.

Nowadays, film scoring has an instantaneousness to it which can be a blessing and a curse. One can score to a cut of a film and try the music against the cut immediately. Some composers refuse to score to picture, preferring to build up an armoury of musical ideas from script alone before trying the music to picture. One instinctively knows when one is on the right path (Hans Zimmer talks about getting the film 'under his fingers') and there must be an element of improvisation to that process of honing ideas. Indeed, composition starts as improvisation, whether in the mind or at the instrument.

But for me, improvising to film has always been a way of discovering the music I didn't know I had in me, inspired by the film I'm working to. I teach improvising to film even to postgraduate piano students at the Royal Academy of Music because it frees up the creative mind, and allows personality to seep through. For years I didn't think I had a recognisable musical voice, but I now realise it's the one I had when I first played silent film piano over 30 years ago. The best score, in the silent or sound films, is the character you can't see on screen, who provides continuous and discreet insight, who reveals and supports, and ultimately makes us welcome.

Neil Brand will be leading an 'Improvising to Film' course during week four of the Dartington International Summer School and Festival. The festival runs from July 29 to August 26 and offers courses, workshops and masterclasses in everything from baroque violin an chamber music, to jazz, opera and musical theatre. Neil Brand's course offers composers and instrumentalists the opportunity to study selected silent classic films, discussing the art of improvisation and ‘reading’ a film, as well as create new music which will be showcased in the Barn Cinema at the end of the week. Neil will also be giving an illustrated lecture as one of the 90 evening concerts and performances during the festival. More information can be found here: dartington.org