Preview: Halle Orchestra/Elder, St Paul's Cathedral, London

Is conducting an orchestra a physically tiring occupation? The conductor Mark Elder, 61, who was knighted in the 2008 Queen's birthday honours list and who is in charge of the Hallé Orchestra in Manchester, is to conduct a concert at St Paul's Cathedral, as part of the City of London Festival.

The concert of works, each one the last by a German master-composer, includes Brahms's "Four Serious Songs" sung by baritone Johan Reuter, two sections of Wagner's opera Parsifal and Richard Strauss's "Four Last Songs", sung by Irish soprano Orla Boylan.

"The experience of conducting is always about getting the balance between your head and your heart," says Elder.

"People often ask, 'are you tired?', at the end. It is the concentration that is tiring. What I do physically I am not so conscious of. I have been doing it for such a long time. It just all comes from inside, but of course how physical the experience is depends enormously on the nature of the music.

"When I conducted Parsifal, which is a very long opera, I did the whole evening in one shirt. You don't break sweat generally in Wagner, but when you are conducting Italian music, it's much more of a visceral and athletic experience. The music is like a coiled spring and the conductor has to energise it moment by moment. When you are conducting German music your role is slightly different: it is to be a calm centre in the middle of the complexity of music."

Elder, a protégé of Sir Edward Downes, was formerly music director of English National Opera and a principal guest conductor of the City of Birmingham Symphony Orchestra.

What are the challenges of doing concerts in St Paul's Cathedral? "I have put together a shortish programme because you don't want it too long – it gets cold and there are no public loos," says Elder. "In a resonant, ecclesiastical building you are on a hiding to nothing. The acoustic tends to swamp the detail of the music."

Tomorrow, 8pm (020-7638 8891)