[Exodus is the Wailers'] most unified U.S. album. If the preceding Rastaman Vibration was Marley's successful stab at joining the sparse repetition of conventional reggae rhythms with the aural density of hard rock, Exodus is a facile interface of Rastafarian reggae-fired dictums and a tender R&B style similar to mid-'60s Motown.

Sides one and two are thematically discrete; the lp's first five songs evince traditional Rasta concerns (the poor man's struggle against civil injustice; religious humility; temporal and/or spiritual flight) with the able Barrett Bros.' thickest steam-crackle-and-pop! bass/drums dialogue since Natty Dread. Laced, as always, with Jamaican folk adages, cuts such as "The Heathen" and "So Much Things to Say" cook with the ominous power that first attracted American listeners to Catch a Fire.

Side two, by contrast, is a full-scale, slightly flawed return to the R&B-rooted love balladry that characterized...