This is where a thirty-something music geek scratches his balding (not bald) head and says, "Geez, has it really been 20 years since that first Jim Pepper album came out?" He pauses momentarily to consider his mortality, then puts this two-disc sampler in the machine and immediately hears David Bowie's "Changes" and Sugar's "Changes" back to back -- two songs that could hardly be more dissimilar, and that together illustrate as well as any could the amazing history of the company that made its name in the early '80s as the world's first CD-only record label. That history is, necessarily, represented a bit spottily on this compilation: Bowie's here, but not Bootsy; Cockburn and Cooder and Cray are here, but not Costello. A few of the inclusions are questionable: Medeski, Martin & Wood's rather lackluster "Bubblehouse" is far from the group's best work for Rykodisc; the same is true of the Jayhawks' laconic "Ain't No End." But there's certainly no arguing with Kelly Willis' grittily brilliant "Take Me Down," Richard Thompson's brutal "Tear Stained Letter," Josh Rouse's "Come Back (Light Therapy)," or Mission of Burma's epochal "Academy Fight Song." And if you've never heard of Osaka Popstar or Alejandro Escovedo, their tracks here may well send you back to the catalog. Yes, it's basically disposable -- the whole idea is to interest you in these recordings enough that you'll acquire all of them and render the compilation unnecessary -- but even so, this 20th anniversary collection is a wise investment and a surprisingly solid listening experience.