Can somebody tell me how to play a triple trill? I read Beethoven used it quite frequently, and I've just found one in the Op. 2 No.3 sonata in C, near the end of the last movement. How can you play thirds in the right hand quickly like that?

Looking at an internet score of the piece the triple-trill in question is on F with the left hand, and B and D a third apart with the right. The fingering on this edition gives 1-2 for the left trill, 2-1 for the lower right trill and 4-3 for the upper.

I'm afraid there's no great trick to playing the thirds at speed; it's an LRSM piece so it reserves the right to be difficult. Practise it slowly, building up speed gradually. Try and keep a flexible wrist, you might need it at speed to help lift 4 up and down.

It's a useful skill in this piece though - the thirds will help the opening of the first movement to really sparkle.

I use fingers 4 & 2 on the D & B, 5 & 1 on the E & C. I cannot play them as quickly as a single trill, so I use a semiquaver rhythm pattern. I adopt this pattern on the preceding single trill, over the lh quavers so there is no change in speed at the double trill.

The sheer effect of the triple trill masks the fact that I am not actually playing them all that quickly.