Unlike their Bristol contemporaries-- Tricky with a steady stream of new mediocre albums; Portishead with a long, long layoff that led to an unexpected and masterful reinvention-- Massive Attack have spent the past 15 years working in brief, intermittent bursts of productivity. Five years separated from , and then another seven elapsed before this year's . They filled the gaps with soundtrack work, but when it comes to Massive Attack the pop group, their albums are still infrequent enough to be sold as events, built up by singles featuring remixes by artists that let the band add the flavor of the current moment, whether that's micro-house circa or spacey electronic disco circa now.