Sibelius’s oeuvre contains four string quartets. They appeared over a long time span and in different phases of his professional career. Most of his early compositions were chamber music, and he composed his three earliest quartets (in E flat major (JS 184, 1885), A minor (JS 183, 1889), B flat major (Op. 4, 1890)) around his study years. They remained unprinted during his lifetime, and the string quartet in E flat major was also not performed in public.

The quartet in D minor Voces intimae op. 56, on the other hand, was completed in London in the spring of 1909, and Sibelius wrote to his wife Aino: “It became wonderful. Just the kind that raises a smile on oneʼs face even at the moment of death.” Voces intimae was published in the same year. Even later, Sibelius seemed to be very satisfied with his composition, for he wrote in his diary: “It is generally claimed to be my best work. I do not think quite that, but it does belong among my best ones.”