Shedding the political themes and global concerns that charged 1960s rock, Disco emerged in the '70s as a pure form of dance-based music. Heavy beats and strong grooves tend to stand above all other elements. Producers like Giorgio Moroder and Van "The Hustle" McCoy manned the boards -- and in some cases performed -- on numerous hits. Most Disco records were cut specifically for clubs to maintain an anonymous, free-spirited vibe. Exceptions to this rule included Donna Summer, the Bee Gees, and KC & the Sunshine Band; Disco acts that invaded the pop charts as the style's popularity peaked. Disco dissolved in the '80s, but its influence is still felt strongly in subgenres like Dance Pop, House and Techno.