Harper--who over the last decade has built a large grassroots following among jam-band fans thanks to extensive road work--will warm up with a March 11 appearance at New York's 575-capacity Bowery Ballroom. Harper's latest album, "Diamonds on the Inside," is set for release on the same day.

The night before, Harper is scheduled to be the musical guest on "The Late Show with David Letterman."

In April, Harper embarks on a lengthy tour of Australia and New Zealand, the itineraries for which are posted at his official website.

After playing a mix of festival and headlining dates in May, Harper will team with fellow singer-songwriter Jack Johnson [ tickets ] for an amphitheater tour that gets underway in June. The itinerary for that outing is expected to surface soon.

"Diamonds on the Inside," which features 14 new songs, is Harper's first studio album since 1999's "Burn to Shine." The new album's track "With My Own Two Hands" is streaming at Harper's website.

In 2001, Virgin Records released Harper's "Live from Mars," a 25-song, two-CD set that was culled from two years of shows. The first disc features Harper with his band, and the second his solo acoustic performances.