There are different ways to upload an audio file and broadcast it using drupal. You can have music auto-play on your homepage or any page you choose.
Here is a simple example of how to embed an audio file:
Another broadcast alternative it to use Drupal's audio module. This allows you to upload audio files and categorize by author, album, etc.
You can use this module to give users the option to play or download a song or audio file. Setting up drupal audio modules is quick and requires no special server setup.