This is a demonstration of K-BMS support of StepMania 4 in the SVN. StepMania 4's BMS file reading support is a bit buggy, so I edited the code a bit to make it sound better.
Keysounds are the sound that you will hear when you press a key, even if there are notes or not, pretty much like DJ MAX, if you don't press the key, there won't be a sound of that note.
Song: Ear Breaker - Super Lovely from DJMAX
The BMS file is converted from the .NMS file that is used with Synth'N. I edited the output simfile (5 keys, hard) to fit it in 4 keys.