By wearing vanilla versions of ceremonial masks to make standing behind a laptop infinitesimally less boring, and playing tastefully edgy hip-hop beats, the SBTRKT project, led by Aaron Jerome, has crossed over, and earned star collaborators for album two. His beats are mostly a cautious version of Flying Lotus’s pimp roll across the stars, or an overstuffed take on James Blake’s emo-jazz arrangements, and work best when they give MCs space to do the heavy lifting: A$AP Ferg is blithe and funny, while Raury’s endurance flow is impeccably weighted. But SBTRKT still doesn’t gel with songwriting. Regular partners Sampha and Jessie Ware fare well, if below their best, on low-stakes piano soul, but more ambitious tracks fail. Vampire Weekend’s Ezra Koenig contrives to make 2014’s longest three-minute pop song, while Chairlift’s Caroline Polachek flails at melody like a drunk with a butterfly net. Is his material demonstrably better than that of most middle-league soul or rap producers? Sometimes, but it’s still a little hubristic to put it out as an artist album.