Call it an ethnomusicological mash-up: Producer Mark Johnson spent 10 years recording musicians from all over the world performing tunes like "Stand by Me," then combined their efforts. The result is acoustic music that's speckled with sounds from Nepal and the Congo but packs few surprises (the safe song choices don't help). On Bob Marley's "War/No More Trouble," Bono's croon joins a Zimbabwean's...