As emotional breakdowns by white rappers go, ''Snowflakes,'' by British newcomer Jack Allsopp, a.k.a. Just Jack, is a keeper: Built on Dre-style strings and Allsopp's brooding rhymes, it's a mesmerizing, wintry sulk of a record, and one of the year's first great singles. The rest of The Outer Marker isn't always as arresting -- his middle-class soul-rap can be too clean-cut for its own good -- but the drum-and-bass pop of ''Triple Tone Eyes'' and the techno-folky ''Ain't Too Sad'' reveal a budding imagination at work.

