The sound comes from MSN Messenger, launched by Microsoft in 1999 and later renamed Windows Live Messenger before being discontinued in 2013 in most countries. Its short alert became one of the defining noises of 2000s instant messaging, heard in homes, schools and internet cafes whenever a contact sent a message or signed in. Clips labelled curto, Portuguese for short, circulate in Brazil and other Portuguese-speaking communities as a trimmed one-second version. It remains popular in edits and memes as a shorthand for old-school online chatting, long before modern smartphone notifications took over.