Playlist.com (http://www.playlist.com ) is the epitome for music in connection to the 21st Century Learning Skills of Create, Collaborate, and Organize. (http://www.p21.org). You can read my thoughts (long form) about it here: Technology Tim's Blog Post on Playlist.com
Free access to lesson plans, blog, resources, graphic organizers, collaborate with other educators using brainpop, interactive whiteboard resources, etc. You can also request an embed code to embed their feature movie right into your wiki!!