Electropop wunderkinds Nipplepeople have been among Croatia’s best-kept secrets for nearly a decade now and yet, even on the Croatian-Serbian music scene where everybody knows them, nobody knows them. The male-female duo insist on anonymity, wearing masks during performances or for rare interviews. They’ve emerged almost yearly since 2009 to debut one new single that’s been processed and reprocessed — a measured, rigorous gestation — until it’s effortlessly up-stirring in its danceable downtempo. The megahit “Frka” is a more understated synthwave, perfectly chilled like champagne. Indeed, the song is a toast to Croatia’s beloved singer Zdenka Kovačiček who recorded the 1981 original. Her 1978 debut offers some seriously quirky funk (“Hello Mr. Elton John”) and a couple of inimitable electronic-driven tracks (“Elektra”) that anticipate the radio-friendlier “Frka”.