Xzibit's catalog stands as one of the west coast's deepest, with records like 40 Dayz & 40 Nightz, Restless, and Man Vs Machine holding heavy replay value to this day. And while there are plenty of highlight cuts throughout his discography, some of the brightest moments arrived under the watchful eye of Dr. Dre, a longtime friend and collaborator to Xzibit. Together, they created tracks like "U Know," "X," "Best Of Things," "Symphony In X Major," "Losin Your Mind," and the notoriously bawdy "Choke Me Spank Me Pull My Hair."

Xzibit Dr. Dre

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And while their collaborative steam tapered off following 2002's Man Vs. Machine, the pair did reconnect on newer cuts like "Louis XIII" and Dre's own "Loose Cannons." Now, however, the duo appears to be in the midst of a highly fruitful creative session. We've already seen Xzibit and Dre working on new music in the studio, seemingly pointing to a new release from X, B-Real, and Demrick's "Serial Killers" collective. Yesterday, X took a moment to reveal that the work has been ongoing, sharing a new behind-the-scenes studio picture on his Instagram page.

"About last night......" captions X, deep in thought as he adds to his book of rhymes; beside him, Dr. Dre contributing his own two-cents. "The almighty D.R.E @drdre and yours truly. I think we are on to something." While it's unclear if these sessions are Serial Killers-related or focused on X's solo music, it's still interesting to see Dre so deeply involved; in fact, this might be the most Dre has been actively contributing to a project since another old friend dropped an album earlier this year. Keep an eye out for more news on this upcoming reunion.