Recorded on 20 March 2013 at London's Wigmore Hall. Composer George Benjamin comments on the two violists' performance of his 1997 work Viola, Viola.

Remember the chords are always, I repeat, like scissors, sshh, so it's not a nice sound, it's *chuh*. [Tabea Zimmermann demonstrates] In the middle, like the bar before B, or [bar] 33, in the middle it's got to come in -- the music mustn't sound homogenous, bits must come out, and the sound should ricochet from each instrument.

At D, keep it softer. The crescendos you're doing are too loud and the dynamic level is getting stronger, so when 'uh uh' came in, it wasn't a shock. Afterwards, also it was much too loud. [Antoine Tamestit plays quietly] So keep things separate and keep the levels of dynamics and attacks and things.

Tabea Zimmermann is the cover star of the May 2013 issue. Click here to find out more.