Three reasons to buy the double CD mix album "The Kings of Electro" — Various Artists (Hostess): It is an excellent introduction to old-school electro, that synth-heavy take on hip-hop indebted to Kraftwerk and funk; it provides a timely reminder that there was computer-generated dance music before acid house arrived; it rocks. The music might sound dated (most of these tunes would have been made on Atari STs and employ a limited number of samples) but the man behind the mix, Playgroup (London-based DJ/producer Trevor Jackson), keeps things interesting by incorporating hip-hop, pop and acid elements.

Unfortunately, the second CD disappoints. Despite Alter Ego's pedigree — his track "Rocker" is one of the biggest electro-inspired club tracks of the noughties — by staying deep and minimal he misses one of the essential points of this genre: It's meant to make you dance. Perhaps the mix's mandate to incorporate a range of contemporary styles influenced by early electro was too large.

With only one man at the controls, another recent mix album "Fabric 36 — Ricardo Villalobos" (Hostess) is more consistently satisfying. Villalobos rewrites the rules of the mix album, having a hand in writing or collaborating on each track. But be warned: The Berlin-based minimal techno producer's funky and at times experimental soundscapes can be disturbing (listen to the frighteningly intense collaboration with Andrew Gillings, "Andruic and Japan").