PREFUSE 73’s new Security Screenings (Warp) is as much a clinic as an album. Few hip-hop producers, mainstream or underground, are capable of creating such dense sampladelic patchworks–Scott Herren not only nicks from a sprawling range of genres, somehow making every chopped-up bit fit snugly among the others, but constructs his tracks so that they develop over their length in satisfying and tuneful ways. On last year’s Surrounded by Silence a distracting parade of guest vocalists and musicians blunted the impact of his production, but the new one puts the focus back where it belongs–there are only two guests, Four Tet’s Kieran Hebden and TV on the Radio’s Tunde Adebimpe, and they appear on one track apiece. Unfortunately this comes off as a retreat rather than a retrenchment: the music is still astonishing, constantly transforming itself and swarming with a ridiculous level of detail, but there’s nothing here Herren didn’t tackle on 2001’s pacesetting Vocal Studies + Uprock Narratives. Maybe with all the projects he’s got going–Savath & Savalas, Piano Overlord, Delarosa and Asora–he’s just spreading his genius a little too thin. –Peter Margasak