The sound comes from Soviet singer Eduard Khil performing a wordless vocalise titled I Am Very Glad, as I'm Finally Returning Back Home. A television performance from 1976 resurfaced online in 2009 and spread quickly as the Trololo meme, with viewers linking its cheerful la-la delivery to internet trolling. The nickname stuck, shortened forms like trololololol spread across forums and video edits, and the clip became a standard reaction for pranks, rickrolls and playful mockery that is still reused today.