According to a recent interview, while working on the Artists United Against Apartheid project, U2's Bono got his first introduction to blues roots when Little Steven loaned him some albums. The experience changed him, and the immediate result was the blistering "Silver And Gold" which closed the Sun City album. That experience infuses The Joshua Tree, U2's fifth and most mature LP, with a seething, exquisitely controlled energy. Bono's vocals burn, channelling his emotional excesses into passion rather than exuberance, and the band matches that performance with an equally precise and powerful one. The Joshua Tree is beautifully produced by Brian Eno and Daniel Lanois (again), who, more comfortable here with the band, seem to deserve much of the credit for the LP's cohesive sound. Steve Lillywhite returns to mix the LPs first three tracks, all of which must be airplay choices, including the luscious single "With Or Without You." But it's the fourth track, "Bullet The Blue Sky," which has the greatest impact. The Edge's guitar stings and Bono's angry growl sings of South American terror. Also try "One Tree Hill," "Still Haven't Found," "God's Country" and the moody, creative "Exit."