Grains of Sand is a compilation consisting mostly of outtakes that never made it onto Carved in Sand, this popular British band's previous, similarly titled album and unfortunately you can plainly see why they didn't. Even though a couple of tracks, particularly ''Mercenary'' and ''Tower of Strength,'' are refreshing in their echoes of the folkie and Eastern-mystic sides of Led Zeppelin, the rest of the record ranges from forgettable to out-and-out embarrassing. In the embarrassing category are the nursery rhyme-like ditty ''Mr. Pleasant,'' the ham-handed, maudlin power ballad ''Kingdom Come,'' and worst of all the mock-symphonic ''Sweet Smile of Mystery,'' which might just be the most misguided sonic blunder since the overblown rock operas of the mid-'70s. C-

