The old BKV signal comes from Budapest's public transport system, where short chimes were used to announce departures and stops on trams and buses. As BKV's branding and onboard announcements changed over time, the earlier signal became associated with an older era of travel in the Hungarian capital. It later circulated online among transport enthusiasts and people sharing memories of Budapest, preserved as a short audio clip. Today it remains popular because it instantly signals Budapest, nostalgia and everyday city life without needing any words or images.