 After writing the string quartet No. 11, Beethoven stopped writing quartets for a number of years, in fact, about 14 years. And it was only after completing his ninth, the choral symphony, that he turned back to string quartets. And then in the course of just a couple of years, he wrote five, the last five quartets. They're known as the late quartets. And groundbreaking, they sound modern even today. They're some of the most remarkable pieces ever composed, I have to say. This is the string quartet No. 12.