Wario Land 4/Sound Room

After beating the Entry Passage, you will gain access to all the passages (Except the Golden Pyramid) and the Sound Room. The Sound Room is the room where all the CD from the CD Treasure chests go when you find them. Some of the CDs are strange or pointless, but they're still fun to listen to.

If you manage to get over 10,000 points in all 18 stages, you will unlock the karaoke mode, with a special song track.