XG is a format just like GM and GS, so every keyboard that contains XG logo on it is XG compatible - the first TG was the MU80. A Tyros is XG compatible as it contains the XG Voice set. XG is more about the manipulation of the sound sources and parameters and is a midi "Standard". Any keyboard that contains "XG" is "XG" compatible, however like all devices, some files will sound more natural than others.