Festival house boils down to a few essentials: stomping beats, irresistible hooks, and invincible vocal melodies. The UK producer Sigala (Bruce Fielder) has all three in spades. A cowriter of Ella Eyre’s “Came Here for Love,” the Norwich native broke through in 2015 with “Easy Love,” unearthing a piano-house anthem lurking within the familiar folds of The Jackson 5’s “ABC.” Time after time since then, he’s struck a similar balance between pop appeal and main-stage power. Pretty much any one of his songs could be a song-of-the-summer contender; they’ve got fond memories of grassy abandon written all over them.