The term "progressive rock", which appeared in the liner notes of Caravan's 1968 self-titled debut LP, came to be applied to bands that used classical music techniques to expand the styles and concepts available to rock music. The Nice, the Moody Blues, Procol Harum and Pink Floyd all contained elements of what is now called progressive rock, but none represented as complete an example of the genre as several bands that formed soon after. Almost all of the genre's major bands, including Jethro Tull, King Crimson, Yes, Genesis, Van der Graaf Generator, ELP, Gentle Giant and Renaissance, released their debut albums during the years 1968–1970. Most of these were folk-rock albums that gave little indication of what the band's mature sound would become, but King Crimson's "In the Court of the Crimson King" (1969) was a fully formed example of the genre. Critics assumed the album to be the logical extension and development of late 1960s work exemplified by the Moody Blues, Procol Harum, Pink Floyd and the Beatles. According to Macan, the album may be the most influential to progressive rock for crystallising the music of earlier bands "into a distinctive, immediately recognizable style".