Any song with the title tag as “Amarok” and Artist name as “Mike Oldfield will cause the following Easter Egg OSd popup:

“One of Mike Oldfield‘s best pieces of work, Amarok, inspired the name behind the audio-player you are currently using. Thanks for choosing Amarok!

Mark Kretschmann
Max Howell
Chris Muehlhaeuser
The many other people who have helped make Amarok what it is”

Here is a Screen shot: