“La Follia”, the madness, was Europe's most contagious tune for three centuries, and in 1705 the young Vivaldi closed his very first published opus by setting it ablaze. Nineteen variations on the old Portuguese dance ground spiral from courtly elegance into genuine frenzy: chattering repeated notes, weeping suspensions, bariolage that sounds like a hurdy-gurdy possessed. It is Vivaldi's audition piece for posterity, and still one of the most electrifying ten minutes in Baroque music.
