We will need a user upload and user voted streaming audio site.
Imagine digg for audio.
There will be a number of admin specified streamed categories. Users will upload audio files into a queue per category. Other users will vote the audio file up or down similar in functionality to www.digg.com.
There will be a an external flash audio player that users can launch to play any of the streams.
An admin designated number of audio files next in line for play will be locked from voting. So for example the first 10 songs in each category will be locked from voting and will play in that order. Once the 1st audio file is done playing the next one starts and the 11th moves into 10th and cannot be voted down.
The site will be free to all users to submit an audio file, but to submit an rss to be automatically feed an audio file in will be a paid service.
There will be advertising throughout the site so we will need an ad management system.