Mark Erelli has his hands full lately. Literally. When I chatted with him earlier this week, he was feeding his 4-month-old son while talking on the phone. Not surprisingly, having a child has put a lot of things in perspective for the Portland-based singer-songwriter.

“Things matter more now, and other things don’t get me down as much,” said Erelli, who will play at the Alamo Theatre in Bucksport on Thursday, Nov. 29, in the first show in the new Over the Bridge concert series. “Everything’s closer to the bone, ever since he came along. All the stuff I write about means more, like what kind of world he’s going to grow up in.”

Erelli’s songs are heartfelt and intelligent, possessing a rootsy charm that puts one in mind of Greg Brown, James Taylor or early Bob Dylan. On his most recent album, “Hope & Other Casualties,” the subject matter spans from the cozily seductive “Snowed In” to the explicitly political “The Only Way,” written in response to Sept. 11. The political content of some of his songs might make people peg him a protest singer, but Erelli shies away from categorization.

“I don’t think a song is going to change the world, but it means very much to me, so that’s why I sing them,” said Erelli. “If it means something to someone else, then great. I don’t think of myself as a protest singer. I just write about what I feel.”

Erelli grew up in Reading, Mass., and studied evolutionary biology at Bates College in Lewiston before pursuing a master’s in biology at the University of Massachusetts. In 1999, faced with the prospect of seeking a Ph.D., he found himself at a crossroads: Music or science?

“I figured, if I don’t try music, I’m always going to wonder what could have happened,” he said. “I was working so hard in grad school, splitting my time between music and school, that I wasn’t really effective in either role. If I could do music spending 50 or 60 percent of my time on it, imagine what I could do with 100 percent.”

Since then, Erelli has released six albums, including the Americana chart hit “Compass & Companion” and 2004’s “Hillbilly Pilgrim,” a departure from his more traditional, straightforward folk songs that found the songwriter embracing western swing, for which he enlisted Boston country band the Spurs.

“I would write those songs in between the more serious, straight-ahead folk songs, just as a kind of sonic sorbet to clear my brain,” said Erelli. “It’s like, I wrote a song about war and the deceit of the president – now I need to write a song about ‘Let’s make a family.’ It was an excuse to really indulge in humor and lightheartedness, in a genre that’s felt really comfortable.”

Obviously, Erelli is an extremely versatile musician – on “Hope,” he plays 11 different instruments, including all manner of guitars, lap steel, mandolin and banjo. Aside from his own recordings, he plays with country musician Lori McKenna in her live band, which garnered him a chance to play with her when McKenna opened for Tim McGraw and Faith Hill on their tour.

Erelli currently is working on his seventh album, an as-yet-untitled disc due in early 2008. He has been playing some of those songs during his live shows, so expect him to bust out a few when he plays in Bucksport next week.

“I think they’re the strongest songs I’ve ever written. It sounds different from everything else,” he said. “They are less guitar-driven. I play acoustic and electric, but we’ve also got keyboards and horns to add different flavors. I play a few in concert and they get the biggest reaction. People want to know what album they’re off of, but they aren’t out yet, which is a good problem to have.”

Mark Erelli will play with Marie Moreshead at 7 p.m. Thursday, Nov. 29, at the Alamo Theatre in Bucksport. Tickets are $15 in advance or $17 on the day of show. For information, visit www.markerelli.com. Other shows in the Over the Bridge concert series include Jess Klein and Chris Merenda on Dec. 13; the Ameranouche Trio and Jay and Bjorn Peterson on Jan. 24; and the WERU-FM Winter Showcase on Feb. 21, all at the Alamo. For information, visit www.myspace.com/overthebridgeproductions. Emily Burnham can be reached at eburnham@bangordailynews.net.