When Maria Muldaur brings her jazz persona to town Wednesday at Blues Alley, it's just a focused version of a passion that has been in evidence for years. She'd included some jazz tunes on her various solo albums, and there'd been traditional jazz tunes as far back as her work with the Kweskin Jug Band in the early '60s. In the early '70s, she toured with Benny Carter and his all-star jazz band and, Muldaur notes, "Three years ago I did a jazz album, 'Sweet and Slow,' on a small but tasteful label with folks like Dr. John, David Nictern who wrote her biggest hit, 'Midnight at the Oasis' and jazz players like Kenny Barron, Ben Riley and Michael Moore."

There was a period, Muldaur notes, when it wasn't unusual for artists to offer a mixed bag on record. "In those days people were not so particular and I was always eclectic. I had these tunes I wanted to do," including a duet on "Old Rocking Chair" with its composer, Hoagy Carmichael, who was actually sitting in an old rocking chair when they recorded it.

Muldaur has just released her second jazz set, "Transbluesency." The title cut is a wordless Duke Ellington composition written for jazz orchestra and female voice "in which the voice is used as another instrument. I've always loved the full title -- 'Transbluesency (A Blue Fog You Can Almost See Through).' It really is a haunting, evocative melody.

"I tried to steer a little left of the standards and not do the same 25 every jazz lady in the world has recorded over and over," she adds. "So many people have done such a good job on some of those tunes. I chose tunes that are a little more unusual, like Fats Waller's 'Massachusetts' -- I used to live in Cambridge -- or Jon Hendricks' 'Where.' "

Muldaur will be joined at Blues Alley by a fine sextet that includes pianist James Williams, bassist Curtis Lundy and trumpeter Don Sickler. "This is the fruition of my dabbling in jazz in the past and I feel real comfortable, but in the future I'll probably be doing more contemporary pop stuff as well. I'm way too eclectic and restless for that."