FransN, at least Korg has dedicated buttons to mute tracks. Not sure about Casio. I can see how Donny expects an improvement by switching it to PSR-SX900, but would it be an improvement in case of CT-X5000 – well, this is how you’ll know it.

Sometimes I think that an option to send a keyboard back actually puts pressure to do it, while lack of such option puts pressure to get along with it and eventually make some use of it. Although there are sometime things hard to compromise, in that case such an option is a solution indeed.