The congas ring cheekily, the cowbell plays a corroded chime, the snare is parched and cruel - and the bass drum, a hard bloom of air, is barely music at all. With these core sounds, abetted by a handful of others, a simple drum machine gave house, techno and hip-hop the language it still speaks today. The Roland TR-808 went out of production in 1983, even as the music that depended on it was being formed. Now Roland has resurrected it as the TR-8. The new model features all the sounds of the original as well as those of its successor, the TR-909 (there is also a relaunched version of the TB-303, the imitation bass guitar that acid house producers used to produce disturbing, squelching undulations). The 909 certainly left its mark, its hi-hats becoming one of the hallmarks of techno's froideur, but it's the 808 that remains the most iconic and influential.