Too many collaborative projects these days are defined by floods of fan tweets and shaky Instagram videos of surprise live appearances — things that feel like they’re more about brand synergy than artistic inspiration. Unfortunately, that’s the impression left by this EP recorded by Big Boi, of legendary Atlanta rap duo Outkast, and upstate New York synth-pop act Phantogram, who appeared on the MC’s last solo LP. Big Grams is split equally between Southern rap (“Put It On Her”) and new-wave noodling (“Drum Machine”), neither of which quite catches fire. The stylistic mashup hits a low with “Fell In The Sun”, where Big Boi slings boring dick jokes (“Talk about a Vitamin D overdose!”) atop overexcited horns and languid synths. Even guest turns from Run the Jewels and Skrillex can’t add enough energy to make Big Grams feel like anything more than an attempt at landing a better festival slot.