Best of the afternoon sets — and perhaps the entire day — was Sky Ferreira, the 21-year-old model-turned-singer who has made headlines for non-music reasons recently. (Ferreira and her boyfriend, DIIV lead singer Zachary Cole Smith, were arrested on drug charges earlier this month. "No, I can't make out with anyone. My boyfriend is here," Ferreira told an adoring fan during her set.) With the release of her oft-delayed debut album ("Night Time, My Time") next month, Ferreira should change the narrative with her strong songwriting (best heard Saturday via the sensual new track, "Heavy Metal Heart"). She is a pop classicist with slightly rough edges, earnestly delivering big choruses with winning sincerity.