Singer-songwriter Brett Dennen gained a lot of television and touring momentum with his third album, "Hope for the Hopeless," released last October. He performed single "Make You Crazy" across the daytime and late night talk show circuit (watch his acoustic performance of the song in the video below), and the album, which reached No. 4 on Billboard's Independent Albums chart and No. 41 on the Billboard 200, is still building.

Dennen's next single will be a new version of the track "Heaven," re-recorded as a duet with Natalie Merchant. The song will be available on iTunes on Sept. 1.

"I'm of the generation that grew up listening to Natalie and the 10,000 Maniacs, so doing a duet with her has not only been a dream of mine for a long time, but doing a duet of a song that I wrote is something that I could never dream up on my own," Dennen tells Billboard.com. "I met her in a studio in the Hudson Valley, and we went for a drive and went to a farmers market and ate some berries and talked about the song, and spent the afternoon recording, and it came out really nice. I think not only my fans but Natalie's fans will really like it."

Dennen has toured with John Mayer and completed a headlining tour this year. He'll launch another trek this fall with Vermont rock band Grace Potter and the Nocturnals, with dates to be announced.

"I'm really excited about this tour because I think it's going to be a little more rocking than tours I've done in the past," says Dennen. "Before when I've taken out openers I've had more of a mellow, acoustic evening. But this tour that I'm headlining in the fall, Grace really knows how to rock it."

In addition, from Sept. 8 through Sept. 22, "Hope for the Hopeless" will be discounted to $5 on the online retailer Amie Street. One dollar from each sale will be donated to the Life is Good Kids Foundation, a non-profit that Dennen took with him on his most recent tour as part of his "Love Speaks" program. For the program, Dennen gives non-profit organizations merchandizing space and stage time to describe their work at each of his concerts.