Like many bands that sold millions of records and dominated rock radio back in the 1960s and '70s, Jethro Tull is not presently a chart-busting act. In fact, the group hasn’t released a new studio album in seven years.

But, like those other bands — many of whom have also gone several years since their last studio disc — Tull is still doing good business as a touring act, playing about 100 shows a year

Many fans at those shows are baby boomers who remember rocking to Tull classics — like “To Cry You a Song,” “With You There to Help Me,” “Cross-Eyed Mary,” “Hymn 43,” “Aqualung” and “Locomotive Breath” — for the first time back in 1970 or ’71.

And they're still jazzed by the group’s dynamic progressive rock mix — which intricately combined rock ‘n’ roll, folk music, jazz and classical elements — and by Tull's often surreal or cerebral lyrics about God, religion, history, social problems, mythology, etc.

Of course, Tull's dominant force, throughout various personnel changes, has always been Ian Anderson, the group’s singer, songwriter, acoustic guitarist and flute player. Back in the ‘70s, Anderson created a theatrical, wildman stage persona, his eyes often popping as he blew a fluttering flute solo while striking his famous standing-on-one-leg pose.

In addition to those Tull concerts, Anderson also does about 25 solo gigs a year. Well, they’re not technically solo gigs — he takes a band out with him — but they're billed as Ian Anderson shows, as opposed to Tull shows.

That’s the incarnation that comes to the Michigan Theater on Wednesday: It’s an Ian Anderson date, and he'll be backed by a four-piece band, including two members of the current Jethro Tull lineup — bassist David Gooddier and keyboadist / accordion player John O’Hara. Rounding the band are drummer Scott Hammond and German rock and flamenco guitarist Florian Ophale.

Anderson’s solo shows are different from Tull shows in that “they allow me to stretch out, and play some of the more esoteric ‘deep cuts’ from Jethro Tull albums, instead of making sure we play all the radio hits,” says Anderson. “I also draw on some songs from my solo albums, and do some new songs. And we can also play more intimate venues, which is always nice.

“The Jethro Tull shows appeal to the more mainstream audience, but in my solo shows, we dig deeper into the catalog, and we do songs that Jethro Tull hasn’t done onstage in many years, or maybe ever.”

As an example, Anderson cites “Wond’ring Again,” from the ’72 Tull compilation album “Living In the Past.” The song was a sequel to “Wond’ring Aloud,” from the enormo ’71 Tull hit album “Aqualung.” “We’ve never played that onstage before,” reveals Anderson during a phone interview from his office, near his home in the southwest of England.

“’Wond’ring Again,’” he recalls, “dealt with some dark subjects, like the dangers of over-population and globalization and such, but we didn’t necessarily use those terms at the time. But when I went back and listened to the song recently, it struck me that everything in that song seems to be applicable to the world today.

“And it's been a long time since Jethro Tull played songs onstage from ‘A Passion Play,’ but on this tour we’ll be playing ‘The Story of The Hare Who Lost His Spectacles.’ Now, whether people enjoy that, or hurl objects at me, we’ll have to see,” he adds with a laugh.

The ‘60s-‘70s was a fertile period for musically ambitious progressive-rock bands, but Tull’s sound was distinct, partly in that English folk music was much more prominent in their mix. (That affinity was most evident on a pair of late ‘70s Tull albums, “Songs from the Wood” and “Heavy Horses,” which boasted a lyrical but vibrant folk-rock sound that, more than anything, evoked the music of Fairport Convention and Steeleye Span.)

And Anderson’s omnipresent flute made them stand out, as well.

Anderson is happy to reflect back on the beginnings of Tull, and discuss what inspired him and the band to cook up such a dynamic mix of disparate styles.

“As a kid in Scotland (he was born in Dunfermline, Fife), most of the music I heard was big-band swing music, the wartime stuff that my dad listened to,” recalls Anderson. “I loved that syncopated feel. Then I got into Scottish folk music, and church music, and then the classical and jazz came later.

“It all started to gel for me as a teenager, and improvisation was a big part of it, too. I always preferred acoustic-based music — I still think of myself as an acoustic musician who has a band that also plays rock ‘n’ roll. And I’ve always loved ethnic music” — a passion that is more prominent on some of his solo albums, which feature him playing ethnic flutes and whistles.

“Now, playing music that combined so many different styles wasn’t always a good thing at first, because people didn’t know what to make of us, but I think we were able to challenge the audience’s perceptions, and give them something different, something they didn’t expect.”

While Anderson has written some new songs that he's playing on this tour, he doesn’t see himself running into the studio to make another album any time soon, for various reasons. First, the audience for progressive folk-rock ain't what it used to be. And veteran bands have long been ignored by most radio stations, who are always panting after the next big youth trend. (Tull continued to release albums in the '80s and '90s, but has not been a regular radio presence since the late '70s, except on classic rock stations.)

Finally, due to downloading, CD sales have plummeted by about 50 percent in the last five years, causing record companies to slash both their marketing budgets and CD prices. So, for an older prog-folk-rock band to spend a load of cash to make a studio album in this climate would not be a wise business decision.

“Plus, there is also the matter of my age,” says Anderson. “I’m 63 now, so, when someone invites me to play in some fascinating part of the world where I have never been, that wins hands down over slogging away in a studio, recording, and over-dubbing, and mixing, and mastering. Like, this year, I went to Armenia twice.

“I go to these interesting places to perform because I know that, at my age, I might not get a chance to go back to them again."

Kevin Ransom is a free-lance writer who covers music for AnnArbor.com He can be reached at KevinRansom10@aol.com.

Ian Anderson performing live in London last year: