Antonio Vivaldi's Opus Four consists of a collection of a dozen concertos for violin, string orchestra, and basso continuo. Owing to some unusual and sometimes daring melodic and harmonic twists it carries the title La Stravaganza (The Extravaganza). The solo music includes a lot of melodic cantabile flights and also a lot of figural passagework that often rises to a virtuosic level. This concerto, cast in two official movements, is the most unorthodoxly organized of the collection. There is no initial ritornello. The soloist glides starts off the opening Allegro with a gliding solo passage that moves over accompaniment from the continuo. Eventually the ensemble comes in and punctuates the solo discourse on several occasions with interludes. A half-cadence in a single-measure Adagio leads to a Presto that features figural solo lines and chordal support and interludes from the tutti, and another half-cadence leads to a transitional Adagio that features sustained chords for the tutti that move through many unexpected harmonic turns and clashes.
