The sound comes from T-Mobile, the mobile network brand owned by Deutsche Telekom, where the five-note melody has served as an audio logo in adverts and on handsets since the early 2000s. Played at startup, it told users the phone had connected to the network. Clips of the jingle later spread to soundboards and meme edits, where this familiar intro sound is now used ironically for any phone, reveal or connection moment, long after the original devices have disappeared.