To promote its new brand of headphones, the Capital, Danish headphone maker AIAIAI teamed up with London-based sound artist Yuri Suzuki to create a London taxi that radiated the sounds of the city. The "Sound Taxi" was equipped with microphones that absorbed the sounds of the city, after which a specially designed software written in Max analyzed the frequencies of the noises and used them to generate music. For example, a low rumble started a bass line or loud hiss would trigger some hi hats, with the street volume controlling that of the music. Passersby heard the music via the speakers and Indian horns mounted on top of the taxi's roof. Inside, passengers could tune into the converted sounds via headphones.