String Quartet No. 3 in G major, Op. 94, by English composer Benjamin Britten (1913–76) was his last completed major work, and his last completed instrumental work. It was written in October – November 1975 during his final illness: the first four movements at his home, The Red House, Aldeburgh, and the fifth during his last visit to Venice, at Hotel Danieli. It was dedicated to the musicologist Hans Keller. In December 1975, brothers Colin and David Matthews performed it privately for the composer in a piano duet arrangement. During September 1976, Britten worked on it with the Amadeus Quartet; who premiered it on 19 December 1976 at the The Maltings, Snape, two weeks after the composer's death.
The quartet is in five movements:
All five movements are in ternary (A-B-A) form. The quartet is in arch form, with a slow lyrical central movement enclosed by two scherzos themselves enclosed by two slow outer movements. English musicologist Peter Evans has remarked that that structure invites comparison with Bartók's fourth and fifth string quartets; only to dismiss that comparison almost as soon as made.
In "Duets", Britten explores all six possible relationships between the four instruments in a quartet.