The client constraint for the app to be designed was that it should be related to music and be for the iPhone. These constraints narrowed our audience but also provided us with unique opportunities such as the ability to assume the possesion of cameras, USB and email, which allowed us to modernize some traditional probe data gathering techniques such as the common inclusion of disposable cameras and envelopes.
This also resulted in more targetted info gathering questions, such as the mix-tape instruction, route mapping and "what do you carry?" page.