Though people have loved their respective music for years, the chance for veteran musicians Donald Fagen, Michael McDonald and Boz Scaggs to play outside their own repertoire is a huge gift.

The three men — all giants of 1970s classic rock in their own right — are coming together for the second time for The Dukes of September Rhythm Revue tour, a show which allows them to explore not only each other’s songs but other classics as well.

“For me the challenges are that I don’t get to play in this context,” said Scaggs. “The challenge is working with material that’s well outside my realm. I would say that’s the challenge for everyone. I get to play guitar styles I wouldn’t normally get to play. This band has a style, and I’m stepping into roles I wouldn’t normally ever play.”

Scaggs joins Fagen, the singer/songwriter/pianist of Steely Dan, and McDonald, the one-time backup singer for Steely Dan who became a hitmaker with both the Doobie Brothers and on his own, for the tour’s stop at Hard Rock Live in Hollywood on Wednesday.

McDonald said that the most fun he and his bandmates have is playing obscure songs.

“We’ve spent a lot of years playing our own material,” he said during a teleconference which featured both himself and Scaggs. “In this realm, we’re playing songs that we’ve never done before or we haven’t done since we were kids. And it’s kind of terrifying at first, but it’s a lot of fun in the end.”

Another reason it’s fun for McDonald and Scaggs is that the tour uses the musicians Fagen has used on Steely Dan’s tours.

“Mike and I got a good chance to fit in (with them),” Scaggs said. “I think what we gained from it was a sense of confidence that we can go where we want to go with these guys. It’s like a Ferrari.”

That allows the musicians to stretch their wings and try to put their own stamp on all kinds of songs — not just obscure but highly familiar.

“For instance, we’ll talk about doing ‘(I Heard It Through The) Grapevine’, but possibly doing the Gladys Knight version, because everybody does the Marvin Gaye version,” McDonald said. “And having one of the girls (in the band) come out and sing it. And I think that’s going to be really kind of fun for the audience, to hear that version live. Because, like I say, most people kind of do the Marvin Gaye version. That’s where the song leapt off in people’s minds. But the other version is fantastic, and that’s really the first version we all heard.”

And that’s really what the Dukes’ review boils down to, McDonald said: Fun for all involved.

“Our aim, I think, is to always pick the songs that when you hear them, they’re the songs that people go, ‘Oh man, I haven’t heard that in years!’,” McDonald said. “But they remember the song.”