The Human League tower over decades of synth-pop. The Sheffield band's influence shines through the colorful funk of the eponymous 1987 single from Living in a Box, and Pet Shop Boys' “So Hard” takes up the glossy timbres and perfect poise of their late-‘80s output. Decades later, Ladytron invoked the New Pop icons with layers of buzzing synths and silky vocals to electrifying effect.