String Quartet in D minor, Op. 56, “Voces intimae”
Sibelius was a middling violinist himself, and he wrote a fair amount of chamber music in his student years, including at least three full string quartets and a number of shorter pieces for four string players. Only one, though, dates from his artistic maturity. The String Quartet, "Voces intimae," was composed in winter 1908-09, between the Third and Fourth Symphonies and during a time of health and financial crises. One of the last pieces he wrote on a four-year contract with the publisher Robert Lienau, it was premiered in Berlin in January 1910.
Often spare and brooding, the five-movement Quartet anticipates the Fourth Symphony far more than it reflects the brighter rituals of the Third Symphony. The subtitle, "Intimate Voices," suggests both the conversational quality of chamber music and the inwardness of Sibelius' ruminations. The work begins with an introductory bit of dialog between first violin and cello, leading into a movement punctuating murmurous figuration with firm chords. A fleetly ricocheting scherzo in A major follows directly, further linked to the first with motivic connections.
A soulful quest for serenity in F major lies at the center of the work. Uncertainty is immediately apparent harmonically in this Adagio, and as the music slithers into a new key area, there are suddenly three detached, soft chords in E minor, remote from any of the previous harmonic implications. It was over these chords that Sibelius wrote the words "voces intimae" in a friend's score, suggesting a personal reference.
Like the first scherzo, the second scherzo is motivically related to the first movement, and it also shares the opening movement's murmuring figures. A more impetuous sort of figuration is prominent in the fiery finale, with more than a hint of folk fiddling. Initially marking the movement Allegro, Sibelius adds più allegro (more lively), then poco a poco più allegro ed energico (little by little more lively and energetic), and then sempre più energico (always more energetic), as the music rushes onward like the homeward bound Lemminkäinen of Sibelius' epic tone poem. This is fiercely accented music of forceful contrasts but irresistible momentum.
— John Henken