'La sfida' is Italian for 'challenge'. The six concerti on this CD are linked in that they all pose particular technical challenges to the soloist - here, Anton Steck. The final allegro of RV264, for instance, relies for its effect on very fast arpeggios spanning all four strings. RV243, meanwhile, is marked 'senza cantin', without the top (E) string. The soloist is consequently forced to reach the upper notes using the A string in the 9th position - getting close to the bridge, in other words. Steck manages all of this without too much fuss. But the question remains: why bother? As an audition piece to see if the soloist has the necessary virtuosity, perhaps. But what is the reward for the listener, especially today when digital sound engineering can mask many a flaw? According to the booklet, these high positions on the lower strings produce a 'dense, muffled timbre ... redolent of the misty lagoon'. A poetic idea, perhaps, but not clearly discernible on my equipment.
For me, these concerti show Vivaldi (an immensely prolific, inventive and inspired composer) at his most showy and his least musical, in works that are, frankly, the complete opposite of those that feature in the excellent Volume 1. Thematically and harmonically, there is little to engage the listener (with the sole exception of the Concerto in g, RV325). If you like repeated passages of rapid, demi-semi-quavers, this could be for you. Otherwise, it will probably seem like virtuosity for virtuosity's sake.