Shooter Jennings will open a series of Charlie Daniels' Volunteer Jam concerts this year, beginning April 11-12 in Harris, Mich. The schedule continues through August and also features .38 Special. Daniels released a duets album, Deuces, in 2007. Jennings also released a new album, The Wolf, last year. The Volunteer Jam began with a 1974 concert in Nashville where Daniels recorded two songs live. "We had such a good time, we decided we should do this once in while," says Daniels.