omPlayer is a special minimalist web browser to comfortably listen to music from online music services. For supported services it lets you control playback from menu bar or from any application with global shortcuts and media keys, supports Growl / Notification Center notifications and Last.fm scrobbling. For other websites additional functionality will not be available but you will still enjoy its unobtrusive behavior.
Currently supported services: Google Play Music, Grooveshark, Pandora, Deezer, Rdio
NoteDue to Mac App Store sandboxing limitations, media keys support is not available out of the box. Please read this blog post for instructions how to enable it.