What happens when you put The Manhattan Transfer and Take 6, two legendary vocal groups with 20 Grammy awards between them, on the same stage?

Those fortunate enough to have tickets for what’s being billed as “The Summit” Saturday at Manchester Craftsmen’s Guild will find out first-hand. The tour has 40-odd dates scheduled between now and March.

“We’re gigging almost every day in a different place,” says Claude V. McKnight III, founder of Take 6 and the only original member. “In this day and time in the music business, it’s a blessing to have that kind of work.”

They were inspired to work together by the amalgam of Chicago and Earth, Wind & Fire, who have made joint concert appearances since 2003. Watching those groups weave in and out of each other’s songs, Mr. McKnight says, “It was so amazing. That’s what we’re attempting to do.”

And it’s not as though The Manhattan Transfer and Take 6 hadn’t known each other previously. The Manhattan Transfer’s Alan Paul says he knew of Take 6 before the lineup even stabilized. “We had in the past done billings together” — including one in Poland — he said, “but the only time we ever did a collaboration was 25 years ago, [when] I put together a benefit for the Boys and Girls Clubs in Newark [N.J., Mr. Paul’s hometown]. We put our heads together in putting this collaboration together.” They did one date, at the Catalina Bar and Grill in L.A. in April 2015, which sparked the current tour.

It didn’t hurt that both groups have the same manager, Ed Keane, who was the catalyst in putting it together.

The Manhattan Transfer was formed in New York in 1969 by Tim Hauser and released a debut album in 1971. Two years later he re-launched the group with Mr. Paul, Laurel Massé and Janis Siegel. Ms. Massé bowed out after a traffic accident in 1978 and was replaced by Cheryl Bentyne. Over the years, the quartet has recorded with the likes of Tony Bennett, Bette Midler, Smokey Robinson, Laura Nyro, Phil Collins, B.B. King, Chaka Khan, James Taylor and Frankie Valli.

The group had its biggest hit in 1981 with “The Boy From New York City,” originally done by The Ad Libs. Also that year its version of the Weather Report classic “Birdland,” with lyrics by Jon Hendricks, earned it a best jazz fusion Grammy. “Twilight Zone/Twilight Tone,” also from the “Extensions” album, borrowed from the TV theme song “Twilight Zone” and made a splash on the disco charts.

Ms. Siegel, Ms. Bentyne and Mr. Paul still remain, and Trist Curliss, now the fourth voice, began subbing for Mr. Hauser when he was battling cancer and replaced him upon his death in 2014.

Although the group does some a cappella work, it has always had a backup band. “We’re a quartet, so we need a little help,” Mr. Paul says. Pianist Yaron Gershovsky has been part of that group since 1979, with a rotating cast of bassists and drummers.

Mr. McKnight, the older brother of R&B singer Brian McKnight, started Take 6 as Alliance in 1980 while a student at Oakwood College, a Seventh-day Adventist institution in Huntsville, Ala. The lineup solidified in 1985 with fellow tenors David Thomas, Mark Kibble and Mervyn Warren, baritone Cedric Dent and bass Alvin Chea. While it began as a gospel group, it branched out into secular jazz, pop and R&B.

A demo the group recorded caught the ear of Jim Ed Norman, who ran the Nashville division of Warner Bros. Records and later became president of the whole label and who, ironically, was supposed to be recording country artists. The 1987 eponymous debut was nominated for a Grammy award, and the group was invited to appear at the ceremony — and after its appearance there received a number of offers for work. The next year Quincy Jones incorporated its talents during a “vocal haze” on the title track of his Grammy-winning CD “Back on the Block.” Since then, it has worked with, among others, Joe Sample, Don Henley and k.d. lang.

Like The Manhattan Transfer, personnel changes have been rare — in fact, only two have taken place since it got started with its international career. In 1991 Mr. Kibble’s brother Joey replaced Mr. Warren, who left to do production work in Los Angeles, and in 2011 Khristian Dentley took over the spot of Mr. Dent, who now teaches at Middle Tennessee State University in Nashville, where it is based today.

In March of this year Take 6 released “Believe,” which includes the current single “You Know You’re in Love,” which features Stevie Wonder.

Putting on such a show of veteran groups does have its challenges, according to Mr. McKnight, starting with them traveling “old school” on sleeper buses. There are different groupings of singers performing on different songs, although all 10 participate at times, and there is a “battle of the bands” section.

Because of their extensive catalogs, “the challenge is what to leave out,” Mr. McKnight says, and “with certain songs, the arrangements for 10 voices needed to be rearranged,” Mr. Paul says.

“We start the show off together, they do some some of their standard things, we do some of our standard things, and we end all together,” Mr. McKnight says. “The permutations are really interesting — that’s what keeps it fresh for everyone.”

Rick Nowlin: rnowlin@post-gazette.com or 412-263-3871.