House music grew out of the post-disco dance club culture of the early '80s. After disco became popular, certain urban DJs -- particularly those in gay communities -- altered the music to make it less pop-oriented. The beat became more mechanical and the bass grooves became deeper, while elements of electronic synth pop, Latin soul, dub reggae, rap, and jazz were grafted over the music's insistent, unvarying four-four beat. Frequently, the music was purely instrumental and when there were vocalists, they were faceless female divas that often sang wordless melodies.