The element of surprise is gone from the mash-up. Hollertronix and 2 Many DJs mastered the technique, made it a staple of their sets, and next, everyone on the block was mix-matching hip-hop to electro and indie rock. The idea that two songs blender-ized can recombine to create something wholly new is thrilling in theory, but the execution is usually sloppy or samey, either simply aligning two similar beat structures or pairing up two completely disparate tracks for the slapstick novelty of a jokey title.

Pittsburgh native Greg Gillis (Girl Talk) absolutely detonates the notions of mash-up on his third album, the violently joyous Night Ripper. Rather than squeeze two songs that sorta make sense together into a small box, Gillis crams six or eight or 14 or 20 songs into frenetic rows, slicing fragments off 1980s pop, Dirty South rap, booty bass, and grunge, among countless other genres. Then he pieces together the voracious music fan's dream: a hulking hyper-mix designed to make you dance, wear out predictable ideas, and defy hopeless record-reviewing.

Night Ripper doesn't stretch the boundaries of mash-ups because there were no boundaries to begin with. As an illegal art form, it's surprising no one came along with an idea like this sooner. Still, it's doubtful they'd have the sturdy, meticulous hand that Gillis flaunts here. The record's pacing is astonishing-- with more than 150 sample sources (all thanked in the liner notes), it ricochets from Top 40 hits to obscure gems and back again like a cool breeze, clocking in at less than 42 minutes. The sampling is pure precision, slotting razor-thin (but highly recognizable) guitar stabs on top of blaring synths on top of anthemic rap couplets and so on, all at breakneck speed.

Part of the fun of listening is trying to figure out the source of each fragment used on these tracks. Familiar as they may be, you'll never place every sample. But at the risk of getting sucked into Gillis' name-game vortex, an example speaks to the power. "Smash Your Head" glides into the siren keyboards of Lil Wayne's "Fireman" less than a minute in, then abruptly shifts into the crushingly dense riffs of Nirvana's "Scentless Apprentice" while Young Jeezy spits the familiar flames of "Soul Survivor", before it all tumbles into a Pharcyde-Elton John-Biggie somersault. On "Minute by Minute", Gillis even slots Neutral Milk Hotel's "Holland, 1945" up next to Juelz Santana's "There It Go (The Whisper Song)". There are no ties, other than the miracle of chopping and looping.

Due to its overwhelming number of unlicensed sources, Night Ripper is practically begging for court drama. In the event of litigation, Gillis' label has armed themselves with a Fair Use argument, citing artists' rights to liberally sample in the creation of new works. Whether that'll hold any water in a courtroom remains to be seen, but for listeners it's an afterthought. Some may dock him points for lack of originality, but Gillis' schizophrenic attitude toward pop music is so novel it's impossible to stay mad at. Time will tell whether it's still fresh in 12 months, when the very recent samples (M.I.A., Gwen Stefani, Webbie) lose their chic appeal next to Smokey Robinson, the Pixies, and Public Enemy-- but for 2006, Night Ripper is the soundtrack of the summer.