“A lot of blues artists, going way back, never chopped cotton,” he emphasized when we talked by phone a couple of weeks ago. “Everybody gets into things that they feel passionately about. I got into it at a pretty early age, being a blues fanatic, and I started playing professionally when I was 19. That was 44 years ago.”

He’s come a long way from those early ‘60s folk revival days when he first attracted attention playing the coffeehouse circuit, aping the great country blues masters who were being worshipped by a generation of white college kids. But unlike most of his contemporaries of the time, he has never ventured far from the purist path he started out on. He drew the material for his self-titled debut album recorded in 1962 from the classic blues songbooks of Robert Johnson, Willie Dixon and Lightning Hopkins, and his latest release, In Your Arms Again, includes songs by Dixon, John Lee Hooker, Ray Charles and Howlin’ Wolf.

Hammond has spent the bulk of his career playing solo, a man alone with an acoustic guitar. He performed here in the ‘80s and ‘90s when Town Point Park hosted blues festivals. The first time I saw him was at Chrysler Hall in 1972, playing his slide guitar as the opening act for John McLaughlin’s electric fusion ensemble, the Mahavishnu Orchestra. Saturday night, he comes to the American Theatre for a rare trio performance, backed up by the rhythm section that played with him on In Your Arms Again.

“I have, on occasion, been offered jobs with the trio,” he told me. “This is one of them. So this is very exciting for us. We played a whole lot of shows when the record was released. It was not big money tours or anything, but it was important for us as a trio to establish our ground. We didn’t get a lot of festival offers this summer that often sustain a trio.

“These guys that I work with---Marty Ballou on bass and Stephen Hodges on drums---are both really talented and have a lot of work. So it’s up to me to get jobs that will work for us. With the trio I play acoustic, so it’s just an embellishment of what I do solo.”

Over the last few years, Hammond has found a stronger, more personal voice. At 63 years old, he has escaped the shadows of his influences and of his famous father. Ironically, though John Hammond, Sr., discovered Billie Holiday, George Benson, Aretha Franklin, Bob Dylan and Bruce Springsteen, his son says he wasn’t the catalyst for his interest in music.

“Maybe partially,” he said, when I asked about his father’s impact on his musical tastes, “but I didn’t grow up with my dad, so I didn’t really get that kind of input that everyone assumes. I got into it on my own, forming my own tastes and my own point of view. My dad certainly, as an advocate of jazz and blues---and his incredible ear for talent---I’m sure it had an influence one way or the other. But in terms of my wanting to get into this, he was very upset when I told him, because he knew it’s a rotten business. So I have undertaken my role in the world with my eyes wide open.

“There were moments when we were close. But I always wanted to keep my distance from his notoriety and fame, and have my own goals and sense of myself. For me, there were times when I just wanted to steer clear of his realm. It was hard to do…he was such a presence in music, a larger-than-life person.”

The impetus behind Hammond’s renewed musical vigor these days is his wife Marla. It was her idea for Wicked Grin, the album of Tom Waits material that earned kudos and brought him widespread attention when it was released in 2001. It was also through her encouragement that he began writing songs of his own a couple of years ago.

“My wife has been instrumental in what has been happening for the last fifteen years,” he said. “We’ve become a team in producing records, going on the road, taking care of business. She’s been my advocate in so many ways. She said, ‘It’s time you wrote some songs.’ And I didn’t think I could, really, and then I did. Now it isn’t that wall of ‘can I or can’t I?’ I know I can.”

I asked him why he had stuck with the blues all these years instead of pursuing the more lucrative world of rock and roll.

“It wasn’t what I wanted to do,” he replied. “I worked very hard in establishing my own world. I’ve made 30 records over the ears and I’ve had a chance to meet all of the movers and shakers of the blues world. To me, it’s a fantastic, deep tradition, and I’m very happy to be a part of it.

“It isn’t a choice to me; it’s my calling.”