The Melos Quartet was active for forty years, from 1965 to 2005. These recordings are from the early 70s, when they had just signed a contract with Deutsche Grammophon. They did no less than the complete cycle. The name Melos comes from the ancient Greek for song or tune. In a clever move it also refers to three of the four members: Melcher and the brothers Voss.
They did the late Schubert quartets later again, around 1989. This is the earlier cycle. It does make me curious about the later version, because this is already quite impressive work.
After an impressive repertoire consisting of several complete cycle of major composers, the group decided to quit. They planned a farewell tour in 2005, and then primarius Melcher died.