Jeff Lonto offers this interesting item:

On September 7, 1971, the Doobie Brothers performed the first rock concert to air live on a Twin Cities radio station.  But the concert was not heard on KQRS; it was heard on WWTC (1280 AM) of all places.

WWTC, then primarily a middle-of-the-road music station, broadcast the concert live from Sound 80 recording studio in south Minneapolis.  The show lasted about an hour and fifteen minutes.  Dick Driscoll (who had moved from KQ to WWTC in 1969) interviewed the band.  Driscoll recalls asking them why they called themselves the “Doobie Brothers” when they weren’t brothers and none of them were named Doobie.

“They looked at me like I was some kind of square,” Driscoll recalls.

Performing the concert on a 5,000-watt AM station gave the Doobies much needed exposure while allowing minimal risk of pirates “Bootlegging” recordings of the show.

A Minneapolis Star article the following day pointed out that the show was unlikely to be bootlegged anyway “because the Doobie Brothers are not an extremely popular group.”

The Doobies would not have their first hit until the next year.  The show consisted of an acoustic set and an electric set.