Alongside contemporaries like the Dave Matthews Band and Phish, O.A.R. (Of a Revolution) helped usher in the '90s resurgence of jam-band popularity. O.A.R. have followed the Grateful Dead's playbook by emphasizing live performances and encouraging fans to tape and share concert recordings. Thanks to this grassroots approach, O.A.R. have become a summer concert season staple, especially among the college crowd. Sure, they've been tagged with the "jam" label, but they tend to offer their tight roots rock and reggae-influenced grooves without many of their peers' long instrumental passages.