Plug - Lightweight OSX player for Hype Machine
Book Playlist - Collaborative music playlists for your favorite books
Magic Playlist - Get the playlist of your dreams based on a song
Playlist Hunt - Playlist Hunt is one of the best applications for Apple users to get the best music through it.
Musicon - An interactive music-making machine for children
Vinyls - Vinyls is a music player that lets you listen to your music without any complicated setup.