When you’ve been making music for as long as Chris Smither has - he released his first album in 1971 -- it’s understandable that, when you hit a certain milestone, you want to do something special to mark the occasion.

For Smither, that milestone will come next year, when he turns 70. So, to commemorate that marker, Smither will release a career retrospective, two-CD set in mid-2014. And it won’t just be an anthology of his original recordings. Smither has re-recorded about 40 of his songs for the project, some that go as far back as that first 1971 release.

“Of course, not all of them will be on the set, but since it’s two CDs, by the time we decide which ones will make the cut, I expect it will have 20 or 25 songs,” says Smither, who, over the years, has used funky, syncopated acoustic blues as his foundation, propelled by his nimble, percussive guitar picking. But he's also drawn on folk, rock, country and New Orleans music to create his distinctive style.

And his songs have frequently been referred to as “cosmic blues,” because he has often tackled heady, larger subjects. “As a writer, I tend not to get specific and personal - I’m more interested in the macrosphere, and our existence as a whole, not just my own existence,” affirms Smither, who comes to The Ark on Saturday. “I’m interested in exploring the meaning of life, the reason for our existence, mortality….”

That’s not to say he’s not also adept at writing about more carnal subjects. Indeed, he is best known for his seductive, sexually-direct (and at times bawdy) song, “Love You Like a Man,” which was covered by Bonnie Raitt on her second album, “Give It Up,” back in 1972, and has been a staple in her live shows ever since -- except she changed the title to “Love Me Like a Man.” It proved so popular that is has been covered by “about 14 or 15” other artists, estimates Smither, including Diana Krall, the Dixie Chicks and Christine Collister.

Raitt’s version has appeared on three of her albums, including a live disc. So, Smither’s songwriting royalties from that song have provided him with a healthy income stream for 40 years. “Yeah, it’s been a nice source of revenue,” says Smither with a wry laugh, during a recent phone interview from his home in western Massachusetts.

But back to his career-retrospective set.

“Since I’m turning 70 next year, my manager and I started thinking that I’ve been doing this for so long that it would be good to release something that spanned my career, which culled songs from all the different eras,” says Smither. “Then I began thinking that I wrote a lot of these songs as a young man, and that that was a young man singing them on those early albums.

“I do the songs differently now - they’ve evolved. I sing them in a lower key than I used to, and I think I’m more convincing as a singer. When I listen back to some of the original recordings, I think, ‘Listen to how high I was singing,’ or, ‘I can’t believe I was playing that fast.’”

Smither’s fans have always been drawn to the rugged, weathered, lived-in quality of his voice. “But basically, in my own mind, I don’t think I really began to sing in a believable way until about 15 years ago,” he says. “I now sing with less caution, and more confidence - a willingness to just let it happen, as opposed to trying to force something.

“I never had any formal training as a singer, so I’ve discovered things over the years that maybe I could have learned earlier, like certain techniques for sustaining notes. And, as a musician, in general, I’ve learned more about controlling the tempos -- not letting the song move too fast.”

Given his large body of work, when it came to choosing which songs to include, Smither took a “committee” approach. “Me, my manager, and my producer (David Goodrich) each made a list of the ones we thought I should include,” says Smither. “Some we agreed on, and some we didn’t, and we finally whittled it down to those 40 or so. Some were easy, because they’re personal favorites of mine” -- like “Train Home," “No Love Today,” “Lola” and “I Am The Ride.”

In some cases, Smither had to re-learn the songs - either the lyrics or the chord patterns -- because over the years he had dropped many of them from his live repertoire to make room for newer songs. “So, some of these songs, when we release this, will be songs that people haven’t heard me do in many years.”

One song he wasn’t sure about including is “Devil Got Your Man.” “That’s the very first song I ever wrote, and Goody (producer Goodrich) insisted that we do it, and it sounds beautiful. It’s one of the best songs on the record.”

Smither’s last album, “Hundred Dollar Valentine,” released last year, was the first disc he’s ever released that consisted entirely of his own songs: He’s always loved finding songs written by other writers, giving them his own interpretations, and including a couple of them on each of his albums. Bob Dylan has been a particular favorite: Smither has recorded five or six Dylan tunes over the years.

“When we were making that last record, I was, as usual, looking for a couple of songs to cover, and Goody said, ‘Why don’t you cover yourself?’ That’s when we first began talking about how interesting it would be to interpret work from my youth, from the perspective of having been on the planet for this long.’

So, for “Valentine,” Smither re-recorded two of his older songs: “Every Mother’s Son” and “I Feel the Same” - the latter of which Raitt also covered.

“So, that planted the seed for this upcoming retrospective - it made us start thinking about doing a whole album’s worth of those -- which then led to us doing 40 and turning it into a two-CD set,” Smither says. With a laugh, he then adds, “Once we got started, I guess we just couldn’t stop.”

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