Dr. Dre is closing in on a deal to sell some of his musical catalogue for over $210 million

According to TMZ, Dr Dre has his sights set on a lucrative music deal, one that would sell the rights to some of his royalties and master recordings ... and we're told the price tag is well over $200 million.

The music mogul is close to selling off some of his music assets in two separate deals ... one with Shamrock Holdings, and another with Universal Music Group ... according to Billboard.

Dre's not selling all of his music ... Billboard characterizes these transactions as mostly "passive income streams" that generate about $10 million annually ... and he's NOT selling his ownership stake in his record label, Aftermath.

Sources close to Dr. Dre tell TMZ ... the actual selling price is actually tens of millions of dollars higher than the $200 million figure Billboard is reporting.