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has wrong-footed fans with the surprise release of Compton: A Soundtrack, the long-awaited follow up to 1999's 2001 and a record that forms part of a return to his roots. While working on the biopic, Straight Outta Compton, hip hop's most-successful producer and businessman had a rethink of musical strategy, deciding to take his operation back to home turf.

He quickly shelved Detox, the album he had been tinkering with for nearly 15 years. On his Beats 1 radio show, The Pharmacy, he explained: "I didn't like it. It wasn't good. The record, it just wasn't good… I worked my ass off on it, and I don't think I did a good enough job."

So, he set to work with renewed focus and made a few phone calls, opting to donate money from the royalties of his latest album to fund a new performing arts and entertainment facility in Compton.

Always at his best when working in collaboration, here's a guide to who's riding with Dre this time...

appears on Medicine Man, alongside South African singer and , another Dre discovery whose name appears often in the new album's credits. Dre told that working with Eminem is always a thrilling experience, not least because he keeps his lyrics to himself until the last minute, including that couplet from The Real Slim Shady about Dr Dre being dead and locked in his basement. "Working with him is crazy," Dre explained. "He never lets me know what he's gonna say until he gets on the mic. My face has been in my hands numerous amounts of times."

Kendrick is the hottest noise and sharpest MC to come out of Compton since, well, you know. So it makes total sense that Dre would bring him in again to work on such a locally themed project. He's on three tracks; Genocide, in which he appears alongside Candice Pillay and British singer-songwriter Marsha Ambrosius of (a particular favourite of Dre's); Deep Water, with new discovery Justus, and Darkside/Gone, which also features North Carolina's up-and-coming 'conscious' rap star King Mez.

As this is a project all about roots, it makes total sense to bring in 's deep soul purr, taking hip hop back to where it came from. She's on the song For The Love of Money, which also features Jon Connor, another Compton rapper snapped up by Dre's Aftermath Entertainment on the advice of (who also appears, on a song called Loose Cannons). Oh, and for another intra-rap link, Jon Connor's most recent mixtape was a reworking of 17 songs entitled The Late Registration Of A College Dropout Who Had A Dark Twisted Fantasy Of 808s And Heartbreak.

This guy takes things right back to the earliest days of Dre's solo career. He's the rapper who helped him build his empire, driving him the furthest from his past in the immediate aftermath (pun intended) of the break-up of N.W.A. So of course 's on the record. One Shot One Kill is a personal warning set to tense, itchy funk. One of the album's highlights, the chorus signs off with a disturbing promise: "You are now not in the presence of nice guys."

And of course, there would be no Beats, no Aftermath, no Eminem, , Snoop and no Compton (the album) without Dre's first group N.W.A. Right at the heart of that group were the twin burning firebrands, street hustler and poet of rage . Cube lends his ferocious flow to Issues, a very Dre production based on a sparkling psychedelic funk sample and bringing in Anderson .Paak and Dem Jointz for extra shouting and vocoder duties.