The late 90's saw the rebirth of a phenomenon that had all but died off (at least in America): the prefab pop sensation. N'Sync, the Spice Girls, and the Backstreet Boys are actually part of a rich (ahem) tradition that includes the Monkees, the Partridge Family, and the Bay City Rollers. These five lads from Scotland were assembled by producers and given an image, some songs, and a script to follow, but, unlike their peers, they actually made some decent music. "Saturday Night" crackles with energy, and a long string of follow-ups bore witness to the both the art and the artifice of pop music. Never mind that they looked pretty ridiculous in their tartans, the music was all right. The old Greatest Hits is an adequate document, but the more recent Definitive Collection has much more bang for the buck.