Drum sound

I had download the code from this page
http://todbot.com/blog/2006/10/29/spooky-arduino-projects-4-and-musical-arduino/

Although the code said it play drum sound, when I connect Arduino with my CASIO CTK-6201, I can only hear piano sound...

Then, I get some demo code from internet, all I can hear is still piano sound....
I wonder it is the setup problem of the CASIO CTK-6201.

Could somebody give me some hints for it ? Is it a problem of GM of CASIO CTK-6201?

You need to check if the code you have is telling your keyboard to change to the drum sounds. Sometimes this is as simple as making sure that the MIDI channel is set to number 10.

Thx, u really help me solve the problems.
I always think that I need to setup something on my MIDI keyboard,
however, the "DRUM" sketch itself is for DRUM MIDI.
As I modify the Channel from x90 to x99, I finally hear drum sound....

Many Thx.