Cannibal Ox’s The Cold Vein raised the bar for New York City underground boom-bap back in 2001. On that album, rappers Vast Aire and Vordul Mega rapped in short bars and slow flows over a dizzying, asymmetrical, gelatinous sci-fi-hip-hop soundscape provided by producer El-P. Whereas most underground hip-hop releases of the time relied on jazz samples laced over straightforward drum loops and rappers forcing similes and punch lines, Vast Aire and Vordul Mega often spoke in metaphor over off-kilter beats, depicting New York City as a bleak, anxiety-ridden metropolis full of vermin and metal, and somehow locating the axis between pre-Giuliani and post-9/11 Manhattan in the process. As a duo, Vast Aire and Vordul Mega have released virtually nothing since The Cold Vein, at least until they dropped their second full-length, Blade of the Ronin, last week (read Leor Galil’s review of the album in our latest record review roundup). They stop by the Abbey Pub on Friday in support of the album; check out “Iron Rose,” which is today’s 12 O’Clock Track and features MF Doom, below.