Rapper Jay-Z [ tickets ] reportedly has signed on as president of the Universal-owned hip-hop label Def Jam.

Under the agreement, Universal is expected to buy the remainder of Roc-A-Fella Records--currently a joint venture with Def Jam--from the rapper and his partners.

"MTV Ultimate Mash-Ups Presents Jay-Z/Linkin Park [ tickets ]"--on which the rapper and the rock act combine their songs (Linkin Park lyrics were used over Jay-Z's beats and vice-versa)--tops the latest Billboard 200 album chart with 368,000 copies sold during its first week in stores.

The set's debut pushes U2 [ tickets ]'s "How to Dismantle an Atomic Bomb" to No. 2 after just one week at No. 1, while former "American Idol" champ Kelly Clarkson bows at No. 3 with her sophomore album, "Breakaway."

Eminem's "Encore" drops two rungs to No. 4, and rapper Nas' "Urban Legend" enters the chart at No. 5.

Rapper DMX [ tickets ] reportedly pleaded guilty on Wednesday (12/8) to reckless endangerment and driving under the influence of valium in connection with a June incident.

At the time, the rapper allegedly crashed an SUV through the gates of an airport parking lot in New York, then--after identifying himself as an FBI agent--tried to drag the driver of another vehicle out of his car.

DMX--whose real name is Earl Simmons--was sentenced to a conditional discharge, meaning that any further violations in the next month could land him in jail. He also paid a fine and surrendered his 1998 Ford Expedition.

Unwritten Law [ tickets ] has canceled its current U.S. headlining tour due to a family emergency, according to Lava Records.

The father of bassist Pat Kim was admitted to a Los Angeles hospital earlier this week "due to an undisclosed, serious ailment," a press release said.

The band was touring in advance of its new CD, "Here's to the Mourning," which is set for release in early February.