Sora and Riku will travel to "Symphony of Sorcery" a new world in Kingdom Hearts 3D: Dream Drop Distance based on the classic Disney film Fantasia. V-Jump revealed the level which shows Sorcerer Mickey standing in front of Sora.
One scene shows Mickey commanding brooms holding buckets and another has Riku in a room with flying music notes. Those notes came from the darkness and it appears Riku has to capture them.
Jump also has a look at Sora decked out in his Tron Legacy costume, which you can see here. Kingdom Hearts 3D: Dream Drop Distance is slated for release this spring.