Technically this song was written for 3 violins and a cello - no viola part, but violas usually pick up the 3rd violin part. I have been in groups where there was no cello, and I ended up having to play those 8 notes 54 times, so I'm feeling his pain! - But I have to say it's one of my all time favourites too - it's just beautiful.
Music fans of any genre, on behalf of the classical world, you're welcome for all of your favourite songs, and sorry for his little bit of rudeness at the end! But this deserves its own post: