New York-based DJ group X-ecutioners have set an April 8 release date for their new album, "Scratchology" (Sequence), which takes a historical look at the art of the DJ with scratch-heavy cuts spannin

New York-based DJ group X-ecutioners have set an April 8 release date for their new album, "Scratchology" (Sequence), which takes a historical look at the art of the DJ with scratch-heavy cuts spanning the annals of hip-hop.

The X-ecutioners -- DJs Rob Swift, Roc Raida, and Total Eclipse -- compiled "Scratchology" as a chronological history of the scratch. The album starts with the likes of hip-hop progenitors Grandmaster Flash and Grand Wizard Theodore and closes with modern tracks by the likes of DJ Q-Bert, D-Styles, and the X-ecutioners themselves.

"The purpose of this mixtape is to educate people about the history of scratching and the scratch songs that have influenced us," explained the group in a statement. "It is by no means a comprehensive compilation, as there are many songs and artists vital to the history of scratching that are not included on this CD. However, it is a great introduction to scratching, its evolution, and the progression of hip-hop from its origin to the present day."

"Scratchology" is the follow-up to 2002's "Built From Scratch" (Loud/Columbia), which debuted at No. 15 on The Billboard 200 last March and has sold 346,000 copies in the U.S., according to Nielsen SoundScan. That album featured the group's collaboration with Linkin Park, "It's Goin' Down," which hit No. 13 on Billboard's Modern Rock Tracks chart.

Here is the track list to "Scratchology":

"Intro -- What Is a Scratch?," the X-ecutioners
"The Adventures of Grandmaster Flash on the Wheels of Steel," Grandmaster Flash & the Furious Five
"Military Cut (Scratch Mix)," Grand Wizard Theodore
"Rock It (Grand Mixer DXT Intro)," Herbie Hancock featuring Grand Mixer DXT
"Like This (Full & Fresh)," Mixmaster Gee & the Turntable Orchestra
"2-3 Break (w/ Dr. Butcher Intro)," Rob Swift featuring DJ Klever & DJ Melo-D
"Ugly People Be Quiet," DJ Cash Money & Marvelous Marvin
"Product of the Environment (Remix)," 3rd Bass
"One For The Treble," Davy DMX
"Shut Em Down (Pete Rock Mix)," Public Enemy
"DJ Premier in Deep Concentration," Gang Starr
"Interlude," the X-ecutioners
"Dilated Junkies," Dilated Peoples featuring the Beat Junkies (Babu, J-Rocc, Rhettmatic & Melo-D)
"Interlude," the X-ecutioners
"Felonius Funk," D-Styles featuring Melo-D, Babu, & DJ Qbert
"Premier's X-ecution," the X-ecutioners featuring DJ Premier
"I'll Kick Ya Ass," Roc Raida
"Razorblade Alcohol Slide," DJ Qbert & D-Styles