Why, you may well ask, would Canadian prog rockers Rush want to cover a batch of tunes from the '60s? And why, you may truly wonder, would anyone other than a diehard fan care? The answer to the first question is simple enough. "We thought it would be a fitting symbol to commemorate our thirty years together if we returned to our roots and paid tribute to those we had learned from and were inspired by," writes drummer Neil Peart in his liner notes. Turns out the second question doesn't need answering. This eight-track EP is clearly aimed at providing devotees with an unexpected treat.

"Feedback" is all flashback -- a short and almost sweetly nostalgic reminder of the days when Peart, singer-bassist Geddy Lee and guitarist Alex Lifeson were cutting their teeth in various bar bands. Rather than trying to reinvent the wheel here, they simply jack it up a few notches in signature power-trio fashion. Lee's borderline cartoonish tenor soars over the rhythmic tumult when the band kicks things off with "Summertime Blues," a full-throated cheer for Blue Cheer. Other, sometimes less likely rock exhumations follow, including Buffalo Springfield's "For What It's Worth" the Who's "The Seeker," Love's "Seven and Seven Is," the Yardbirds' "Shapes of Things," and Cream's version of "Crossroads." There are twists here and there -- Lifeson's solo on "Mr. Soul" alludes to the Byrds' "Eight Miles High," for example -- but mostly the band's take on the past is gleefully loud, affectionate and faithful.

No, "Feedback" isn't likely to snare new fans, but as concept discs go, it's refreshingly uncomplicated and unpretentious.

-- Mike Joyce

Appearing Tuesday at Nissan Pavilion. * To hear a free Sound Bite from Rush, call Post-Haste at 301-313-2200 and press 8109. (Prince William residents, call 703-690-4110.)