LONDON, Ont. -- Bachman Cummings still have some overdrive left in the tank.

With Burton Cummings, one-half of classic CanRock's dynamic duo, apparently feeling one more slow song might put a good show on to autopilot, it was time to switch gears at Harris Park last night. It was time for "some straightahead rock 'n' roll," Cummings said, talking to the band as much as the crowd of about 9,500 cheering fans.

"We're changing the set -- this is like Bruce Springsteen," responded the duo's other member, Randy Bachman.

Whatever slow one had been in the set list, it was blown away by a Cummings special, My Own Way to Rock. Then Cummings introduced a song he said, "Randy wrote when he wasn't very fond of me."

That was the cue for Hey You, one of the lesser hits for Bachman-Turner Overdrive, Bachman's band after he left Cummings and the Guess Who.

Last night, at Harris Park, Hey You -- with its overdrive from the stars and the band and the singalong from the fans -- blew away the BTO original.

It was a big moment, a signal that Bachman Cummings -- our two heroes and a crack backing band -- are still finding ways to keep their songbook new.

The four-day classic rock fest that ended last night at Harris Park is called OMAC Presents the Hawk Rocks the Park's Fifth Anniversary. Rock the Park V is a little easier to shout into the evening. So let's use that. Kenny Shields & Streetheart opened late in the afternoon followed by Canadian rock band April Wine and Michigan legend Mark Farner. The festival is a fundraiser for the London-based Bethanys Hope Foundation.

Bachman Cummings represents the reality that even if somebody else owns the Guess Who songs, the Winnipeg duo owns the songbook and its fans. That songbook includes hits from their period together in the Guess Who, from the time when Bachman left and Cummings stayed, and from Bachman-Turner Overdrive and Cummings' solo career.

The set list for the first 30 minutes was extraordinary. Check it out and pick the potential encores.

American Woman. Looking Out for No. 1. Albert Flasher. These Eyes. You Ain't Seen Nothing Yet. Clap for the Wolfman. Let it Ride.

There are probably three or four in there, including American Woman, which they like to ease into with a bluesy start before Bachman powers into the riff that made the song a hit.

"Burton and I are thrilled to be here. We come here every so often . . . We're celebrating four decades of making rock 'n' roll together," Bachman told the crowd early in that expert run of hit after hit after hit.

The three-decades plus since Bachman-Turner Overdrive ruled the world have taken some edge and power from Bachman's voice. On guitar, he is still on fire. Looking Out for No. 1 --which must be an in-joke to play as the second song on the night -- he was jazzy and a complex marvel. On Let it Ride, he rocked and sounded sharp enough to give lessons to the boatload of guitarists in most of the other 14 bands on the Rock the Park V bill.

Bachman and Cummings also shared stories behind some of the songs. Having heard those intros a few times, this critic recognized when the story and punch lines had been twisted a bit. Cummings had his eco-conscience on his sleeve for Hand Me Down World. "Hope some of you remember this because it makes a lot of sense in 2008," he said after saying the song came from "the days of the hippies."

Bachman Cummings have significant London ties. Legendary Canadian record producer and longtime London resident Jack Richardson worked with the Guess Who when he was in Toronto and helped shape their songs and albums. Richardson produced 14 Guess Who albums from 1969 to 1975.

He's the producer Cummings talked about in the introduction to No Sugar Tonight/New Mother Nature, two songs they mashed into one. "Our producer at the time (Richardson) thought we were geniuses and after four decades . . . I'm beginning to think he was right."

There were still hits to come -- but the two rockers had shown they really do have their own way to rock.

A guitar signed by the Canadian rockers is to be part of the silent auction during a fundraiser at the London Music Club this afternoon.

April Wine, who played earlier in the day, may be back in downtown London for a free concert at Victoria Park, late next month.

If so, Oowatanite would work as a finale. It was the fans' choice last night.

"You ever want us to come back, just holler. We're just across the lake," Farner told the crowd after a set of hits from his Grand Funk Railroad days including We're An American Band, Some Kind of Wonderful, Bad Time and Locomotion.