Signature Theatre in Arlington is helping expand the American Songbook to include rock and pop classics of a half century ago in cabaret shows this winter that will celebrate Leonard Cohen, Joni Mitchell and Burt Bacharach.

And currently, as its bigger stage extols the virtues of different original American music genre (at least in title)  with “Ragtime,” the cabaret centers on the many splendors of soul.

That means Motown, yes, but also the stars of Stax, the gospel tinged soul of Ray Charles and Sam Cooke, the attack of James Brown and the folk-tinged approach of Bill Withers. It’s a very wide and rich field of music that could happily go on for hours.

It’s the images of Charles, Withers and D.C.-born Marvin Gaye that advertises the current revue “How Sweet It Is: The Men of Soul” at Signature. But while there’s only one Ray Charles number in the show, Withers and Gaye, whose 1964 hit provides the title for the show, get three each.  

Otis Redding’s songbook also provides a trio of goodies. And the smooth-voiced Cooke, whose “Twistin’ the Night Away,” kicks off the set, gets four. 

Despite the high energy of a lot of the classic songs, affable singers Derick D. Trudy Jr., and Isaac Bell, who calls himself Deacon Izzy, are on stools from the start. And when they urge the frankly elderly crowd to “lean up” and “lean back” in their seats in the opener, it’s a little bit like chairzersize.

There’s no denying there’s a lot of fun, though, from the duo backed with a quartet of musicians trying their best to cover a lot of ground. 

Bell and Trudy preface some songs with personal remembrances, about relatives who struck out in the dating game (as in Cooke’s woeful “Another Saturday Night”) or of church and memories of grandma (Wither’s “Grandma’s Hands”). 

The two didn’t show particularly notable harmonies together until about six songs in, on Cooke’s “Bring It On Home to Me.” About that time you wish musical director Mark G. Meadows had included more Sam & Dave deep cuts — from “Soothe Me” to “When Something is Wrong with My Baby” — to take advantage of the yearning sound they’re able to make together.

As it is, the lone Sam & Dave selection was the back and forth of “Soul Man” (with talented keyboardist Joshua Jenkins having to provide its signature guitar lick via piano). 

There was a natural emotional climax mid-show when Gaye’s classic and ever-timely “What’s Going On” (with a fine sax solo from Trey Sorrells) was capped with the equally stirring Cooke powerhouse, “A Change is Gonna Come.”

But then it was back to the party with Gaye’s lightweight disco stab “Got to Give It Up” (poached in a 2013 Robin Thicke hit that led to a celebrated court case). This time, it was infused with a bit of The Jacksons’  “Shake Your Body (Down to the Ground)” as well.  

Along with the casual, almost offhand presentation of the material, there was a sense it may have been underrehearsed. Jenkins had to make some frantic overhead motions as some songs were coming to the end; at another point when Bell wanted the band to bring it down or stop altogether as he made a point about the audience standing to dance, drummer Joey Antico acted like he had never heard of this standard soul band direction and kept pummeling on. 

The good news was that the audience stood anyway, not needing much prodding to get up and groove with the most excellent sounds being resurrected. 

“How Sweet It Is: The Men of Soul” runs through Nov. 19 at the Signature Theatre, Arlington, VA.