Ben Harper and Jack Johnson will embark on a co-headlining summer tour of about 40 North American dates beginning in June, sources tell Billboard.com. The pair is expected to play venues ranging in si

Ben Harper and Jack Johnson will embark on a co-headlining summer tour of about 40 North American dates beginning in June, sources tell Billboard.com. The pair is expected to play venues ranging in size from 5,000 to 25,000, mostly outdoors. Harper and Johnson are already set to team up on a 13-date trek through Australia and New Zealand, beginning March 29 in Auckland.

The duo will also take their respective shows to the Coachella Valley Music & Arts Festival in Indio, Calif., in late April, the New Orleans Jazz & Heritage Festival in early May, and the second Bonnaroo Festival on June 13 in Manchester, Tenn.

Harper will be supporting his upcoming album "Diamonds on the Inside," due March 11 from Virgin. Album track "With My Own Two Hands" can be sampled from the artist's official Web site. The new set is the follow-up to 1999's "Burn to Shine," which debuted at No. 67 on The Billboard 200 and has sold 503,000 units in the U.S., according to Nielsen SoundScan.

Johnson's next Enjoy/Universal album, "On and On," arrives May 6. It's the long-awaited sequel to his 2001 debut, "Brushfire Fairytales," which peaked at No. 3 on Billboard's Heatseekers chart and No. 34 on The Billboard 200. It has shifted 1.1 million copies in the U.S. to date.