I spoke too soon when I said earlier that there was no way to access the CTK-800's panel sounds (see here). It was there in the manual all the time and I didn't find time reading it. The appendix of lists all the instrument's sounds with their corresponding Program Change and Bank Select MSB values. For example, to select 000-Stereo Grand Piano, you have to send the Bank Select MSB value of 2 and Program Change value of 0 to the keyboard. How? Well, you need a software that could handle the task. The basic Anvil Studio package does not provide a way, although I think, you can buy additional accessories that could provide Anvil with this functionality.
This brings me to the most common (and some consider it the best) sequencing software available. I am talking about Cubase, of course. In this article, I will discuss briefly how to set the Bank Select MSB values and Program Change values using Cubase in relation to the Casio CTK-800 keyboard.