Miguel, remember, I do not possess a BK-9 keyboard myself.

I located and referred you to the manual. The manual says the files should be type SMF, extension .mid

The thread on the other forum suggests it might be wise to format the USB stick on the BK-9 itself, rather than a computer, before loading files.

Please read the manual and try something and see if it works.

Last edited by Mark Hayes; 11/15/21 04:35 AM.