At one point Sunday night at the Oakdale Theatre, Bonnie Raitt said it’s taken 40 years to get Taj Mahal and her together for a tour. Too bad it took that long.

It’s understandable of course. Both have had successful careers in their own right, particularly Raitt, whose career exploded in the late 1980s and early ’90s with not only chart success but also a plethora of somewhat unexpected Grammy Awards.

Well, they’re together now. And their third show of the one-month BonTaj Roulet Summer Tour was a blues explosion with each playing with their own bands, Taj joining Bonnie for a couple of acoustic numbers and then both bands playing together to seal the deal.

Taj came out first at the Wallingford, Connecticut venue and cruised through a bluesy 45 minutes with his swinging Phantom Blues Band, which includes Mike Finnigan, who has played with everyone from Dave Mason to Jimi Hendrix to Les Dudek, on keyboards, soulful guitar player Johnny Lee Schell, horn players Joe Sublett (sax) and Darrell Leonard (trumpet) and bass player Larry Fulcher.

Taj opened with a smoking instrumental, then played Diddy Wah Diddy, a song The Remains once covered, Hello Josephine, and his seminal version of Fishin’ Blues, among other tunes, before hitting a high with Going Up To The Country, Paint My Mailbox Blue from perhaps his greatest album The Natch’l Blues. Mailbox had an easy going yet smoldering, jazzy feel that featured a solo by Schell that was cut from the mold of the Jesse Ed Davis original in 1968.

Taj, whose voice is in fine form, looked relaxed, was his usual jovial self and switched from electric to acoustic guitar and harmonica during the set. After Mailbox, they played the jazz-inflected Senor Blues that Taj remarked was written by “Horace Silver from Norwalk, Connecticut,” which raised a cheer. The band handled the piece elegantly with Fulcher’s riveting bass line, a smooth horn arrangement and exceptional solos. Another instrumental concluded the set.

Bonnie Raitt came out about a half-hour later and I have to admit although I’m a bigger Taj fan, she took everything up a level. She ran through many of her hits and most recognized tunes, playing them all brilliantly on slide and showing off her considerable skills as a singer, perhaps the best female blues singer of our age. The set included Thing Called Love, Something To Talk About, Love’s Sneakin’ Up On You and Love Letter as well as some newer tunes that included Taj’s horn section.

She brought Taj out for a stunning duo on which she played dobro and Taj electric-acoustic for his I Done Changed My Way Of Living, also from Natch’l Blues. They traded vocals and Bonnie provided the ultra-bluesy feel with her slide answers. Taj then sat down at the electric piano and they played a blues that seemed to be taken from several sources with lyrics from different classics in each verse, including Mean Old World and Blues With A Feeling.

Taj departed briefly as Bonnie brought her band back and blew the house away with her reading of Angel From Montgomery. After a few more tunes with her band — which includes Ricky Fataar on drums, with her since 1981, Hutch Hutchinson, bass (1983), new member Ricky Peterson, keyboards, who took several vocal turns to good effect including Bobby Womack’s Good Man, Good Woman, and guitarist-producer George Marinelli, whose parts were perfectly placed and who soared on several solos — she ended with another stunning ballad in I Can’t Make You Love Me, a huge crowd-pleaser.

She then surprised the crowd by bringing out Al Anderson, a Windsor, Connecticut legend who played in the Wildweeds, NRBQ and has had a long and vastly successful career as a songwriter in Nashville. They played Green Lights, a Q song, on which Anderson played two fiery and penetrating solos on a Fender Telecaster. She did this another time at a concert I saw at the old Oakdale, during probably one of the last seasons of the original theatre-in-the-round, which at that time had a wooden dome, now the lobby of the new Oakdale. At that show, they played Me And The Boys.

After a brief break, not more than a couple of minutes, came the part everyone was waiting for, a full blown high-octane set with Bonnie and Taj centerstage and both bands cooking together. It didn’t disappoint. The material ranged from funky R&B to blues, swing and calypso and hit a high point with yet another Natch’l Blues tune, She Caught The Kay And Left Me A Mule To Ride. The set included about seven tunes and rocked the full house, which stood through most of it. Then it was over. No encore. But, of course, that whole concluding set was the encore.

There’s no doubt some of the collaborations were a little rough around the edges, probably because this is the start of the tour. But those issues were slight in comparison with the momentus occasion of two modern day blues greats collaborating for the first time on tour and showing the audience so much about our musical heritage and in such a soulful way.

You can catch a video of the two together on the Today Show here.