MSN Messenger launched in 1999 as Microsoft's instant messaging client and quickly became the default way teens and office workers chatted online. Its new-message chime, a short synthetic pop, played millions of times a day during the service's peak in the early 2000s. After Messenger shut down in 2013, the sound lived on through nostalgia compilations, retro tech videos and meme edits recreating old desktop screens. It still works today because a single blip instantly signals the early social internet era, much like the modern Discord notification does now.