Music Night app for iPhone and iPad

Ural Music Night is a large music festival that takes place in Ekaterinburg. During one night musicians and bands of various styles play on 50 stages of the city.
We place a special spectrogram mark on every piece of branded content and advertising. Its an image that can be decoded into a sound. A Music Night app can scan these marks using the smartphone camera.

[ How to use ]
Just point the camera at the mark, so that you can see the whole mark on the screen. When the app catches the marks, it begins playing music.