Mickey Hart is a rhythm proselytizer. He's been sounding-off from the percussion pulpit since writing his first book, Drumming at the Edge of Magic in 1990. Hart's Planet Drum--the book and the album--set forth an army of percussion acolytes. With Spirit into Sound, Hart has another accompanying book and a gentler music that looks toward the melodic side of percussion. Although there are a few guests, including tabla player Zakir Hussain, Grateful Dead guitarist Bob Weir, and sarangi master Ustad Sultan Khan, it's Mickey Hart and vocalist/percussionist Rebeca Mauleon who dominate the album. They play melodic percussion instruments and/or electronic samples of African balafon, Brazilian berimbau, and steel drums. For a drummer as worldly as Hart, Spirit into Sound is surprisingly naïve in its childlike rhythms. Mauleon's wordless chants make Spirit into Sound sound like a global glossolalia nursery rhyme. This isn't an album for the rhythmatists of Hart's core following, but a more intimate affair. --John Diliberto