The Nokia tune is based on Gran Vals, a solo guitar piece written by Spanish composer Francisco Tárrega in 1902. Nokia adapted a short phrase from it in 1994 for the 2100 series, and it became the default ringtone as mobile phones went mainstream. At its peak it was heard billions of times a day around the world, making it one of the most recognised melodies ever. Online it survives as a meme and prank sound, used to imitate an old phone ringing or to trigger instant nostalgia.