A DJ’s job is to throw a party, and that’s what DJ-turned-It-producer Diplo does with his reggae-centric side project. The guest list is crazy: “You’re No Good” mashes up Santigold, R&B folkie Danielle Haim, Brit soul newbie Yasmin and dancehall don Vybz Kartel; “Get Free” wraps Amber Coffman of Dirty Projectors in a lover’s rock groove; “Jessica” finds Vampire Weekend’s Ezra Koenig in a stoner-dub haze, pining in German. It’s less strictly Jamaican than Major Lazer’s debut, connecting reggae’s often-insular tradition to a wider world. That may not impress those who find Diplo’s culture-jumping suspect. But it makes for rich fusion, and a hell of a party.