La stravaganza was published in Amsterdam around 1716 by Estienne Roger as Vivaldi's opus 4 and dedicated to Vettor Delfino, a young Venetian nobleman who had studied the violin with the composer. The title, extravagance, points at the harmonic and figural surprises that run through the twelve concertos. Number one is in B flat major, number two in E minor; the second in particular sets the solo violin against the ripieno in long, obsessive sequences. Walsh reprinted the set in London soon afterwards, which is how it reached English players.