The Sheepdogs are a band that looks back fondly to the classic rock past. The Canadian group is most notorious as the act that won Rolling Stone magazine’s “Choose the Cover” contest, and as a result will go down in rock history as the first unsigned band to appear on the rag’s cover. Not that they stayed unsigned for long after that. After getting the attention, the band signed a deal with Atlantic and recruited Black Keys drummer Patrick Carney to handle production duties on their major label debut. They perform tonight at 8 at the Beachland Ballroom. Tickets cost $18 in advance, $20 at the door.