Many notable events happened during the "grunge era" of music that may not have happened had grunge never become popular. Alternative rock, previously heard mostly in local clubs, on college radio, and on independent record labels, became popular in the mainstream as major record labels sought out more previously obscure music styles to sell to the public. The traveling festival Lollapalooza came about as a result of this, with grunge being a major part of the 1992 and 1993 events. In the media's spotlight, grunge became part of the pop culture, most notably being a major part of the 1992 film Singles, which featured several grunge bands. Nirvana and Sonic Youth would star in a documentary film that same year, 1991: The Year Punk Broke. Riot grrrl, another hardcore punk offshoot that came into being in Western Washington (and was thus often seen as the feminine equivalent of grunge), became well known from the media coverage of the local scene. With such punk derivative genres becoming popular, punk itself was able to make a revival, as bands such as Green Day and The Offspring became chart-topping successes. Independent record labels, which used to rarely have success on level with major labels, were able to sell albums with equal or similar success as the major labels (most notably in the cases of Sub Pop and Epitaph Records).
