Years & Years are disciples of dance music, freely playing with classic and contemporary forms and rhythms. Songs like “Real” and “Worship” tap into the escapist throb of deep house and the giddiness of ’80s synth-pop. On “Shine” and “King,” Olly Alexander’s lush voice reminds us that Communion is a pop affair at heart. “Memo,” with its tender falsetto and piano, would convert Sam Smith fans. Packed with peak-hour anthems and lighters-aloft ballads, Communion is a dance-pop album that will hold up for decades to come.