The two principal violinists in Prince Leopold’s orchestra, Joseph Speiss and Martin Friedrich Marcus, had both been recruited from Berlin. The Concerto in D minor for two violins (BWV1043) was presumably written with these two talented players in mind. The first movement introduces fugal writing into a concerto form: the opening fugal ritornello (a recurring passage, varied in length and by transposition into other keys) is repeated three times during the course of the movement, with the later repetitions shortened, and in between these central pillars come brilliant episodes for the two soloists, treated so equally that both players play each melodic phrase. The Largo ma non tanto, with its beautiful cantabile melodies, has become one of the best known of all Bach’s concerto movements, with the soloists’ theme being treated fugally, and the tutti strings providing harmonic support. The final Allegro is in conventional concerto form, with the soloists leading the ritornelli as well as the episodes. But here, as in so much of Bach’s writing, the accompanying orchestra too has music of excitement: the main theme twice appears in the first violins whilst the soloists present more lyrical material, and the accompaniment also provides a series of short imitative phrases which are thrown rapidly between the various sections of the orchestra during the soloists’ episodes: insistent unison arpeggios in all the upper strings make the two passages of double stopping from both soloists all the more exciting.
from notes by Robert King © 1989