One of the most powerful figures in the music industry, Mr. Iovine, 61, brings to Apple deep celebrity connections. Mr. Iovine’s relationship with Apple dates to the beginnings of iTunes, when he became a friend and crucial advocate for Mr. Jobs. Mr. Iovine and Dr. Dre — whose real name is Andre Young — will join Apple in senior positions reporting to Mr. Cue, and Mr. Iovine will leave his longtime post as chairman of Universal Music Group’s Interscope Geffen A&M division, where he has guided the careers of U2 and Eminem. Mr. Iovine got his start as a studio gofer in the 1970s, but quickly made his name as an engineer and producer, working with acts like Bruce Springsteen, Tom Petty and Stevie Nicks. Mr. Iovine and Dr. Dre will each earn hundreds of millions of dollars from the Apple deal. Interscope Records, which Mr. Iovine founded in 1990 with the retail heir Ted Field, became the hottest label of the 1990s.