Just last week, DJ Mustard dropped his mixtape 10 Summers. Now the L.A. hitmaker lets go of a track that didn’t make the cut. In advance of his HARD Summer set this weekend, Mustard connects with Ty Dolla $ign and ILoveMakonnen on “Why’d You Call?” Ty$ lends his signature West Coast flow, while Makonnen adds his gooey baritone to the ricocheting banger, which builds into an all-out electro jam.