Jimi Hendrix, Janis Joplin, Lennon–McCartney. Names which not many people would expect to hear in conjunction with a string quartet. But the boundaries between classical...

Jimi Hendrix, Janis Joplin, Lennon–McCartney. Names which not many people would expect to hear in conjunction with a string quartet. But the boundaries between classical music and other music — pop, rock, jazz, ragtime — are not so well–defined. In fact, in the ten years between the 20st and 21st centuries, they have become ever more blurred.