In many ways, 1999 didn’t make any musical sense.

A peer-to-peer file-sharing site set up by Shawn Fanning and Sean Parker became an industry-shifting phenomenon called Napster. Who could have guessed that we’d stop buying albums?

Well, actually, David Bowie. He became the first commercial artist to make his new studio project available for download, a full two weeks before it arrived on store shelves.

It got stranger. The year's last nine Billboard Top 100 lists were capped by Carlos Santana, who found himself in an entirely unlikely spot performing with an even more unlikely singer. Who could have guessed that all Santana – who hadn’t reached the Top 10 since 1970, and had never had a No. 1 song – needed to do was start working with the guy from Matchbox Twenty?

Or that the Flaming Lips would finally notch their long-awaited breakthrough? Or that Styx’s long tenure with Dennis DeYoung would come to a crashing halt?

Artists like Paul McCartney, Crosby Stills Nash and Young, and Def Leppard looked back, even as new-guard acts including Blur, Wilco, Sleater-Kinney and Built to Spill pushed bravely forward. (Jeff Beck split the difference, applying modern elements to his familiar tricked-out fusion sound.) Perhaps unsurprisingly, Sammy Hagar was in the mood to party. So, okay, everything wasn't unfathomably weird.

Still, this was a year in which boy groups dominated the charts, and Britney Spears and Christina Aguilera battled in gossip news, while Nine Inch Nails was pushing into the mainstream with their first-ever chart-topping album and punk made a (poppier) return with blink-182.

That made picking 1999’s Best Rock Albums a unique challenge. But some rose to the top.