Word spread through underground channels. Artists came like moths—producers, street poets, a retired violin dealer with ink-stained fingers. They traded secrets and beats, but they didn’t steal the app. The Locksmith’s build only permitted one exclusive install per device ID, and rumor said the APK chose its user, not the other way around. That’s how the city ended up with a dozen living soundscapes: a cafe where the chairs hummed harmonies at closing, a laundromat whose cycles spun out slow, orchestral crescendos, a bus route that whispered syncopated confessions through the PA.