The Second Summer of Love is a name given to the period in 1988–89 in Britain, during the rise of acid house music and the euphoric explosion of unlicensed MDMA-fuelled rave parties. The term generally refers to the summers of both 1988 and 1989 when electronic dance music and the prevalence of the drug MDMA fuelled an explosion in youth culture culminating in mass free parties and the era of the rave. LSD was also widely available and popular again. The music of this era fused dance beats with a psychedelic, 1960s flavour, and the dance culture drew parallels with the hedonism and freedom of the Summer of Love in San Francisco two decades earlier. Similarities with the Sixties included fashions such as Tie-dye. The smiley logo is synonymous with this period in the UK.