The use of guitar solos in hard rock and heavy metal was notable during the 1980s, when rapid-fire "shredding" solos were common; a virtuoso lead guitarist of a band might be more well-known than the singer (although in a few cases one artist held both roles). During this time, players began to use advanced harmonics techniques more widely. Later, guitarists who had developed considerable technical facility began to release albums with instrumental-only guitar compositions. Guitar solos in popular music waned in fashion in the middle 1990s, coinciding with the rise in popularity of nu metal and grunge. Nu metal differed significantly from previous sub-genres of metal and abandoned guitar solos altogether, except for a few rare lead fills here and there, whilst grunge did not wholly abandon solos and included them from time to time. Guitar solos likewise became less prominent in many pop and popular rock music styles; either being trimmed down to a short four-bar transition or omitted entirely, in a vast departure from the heavy usage of solos in classic rock music from the 1960s, 1970s, 1980s, and early 1990s. Classic rock revival music heavily features soloing, along with classic rock bands that are still active as of 2018.