I'm a little stunned that the 7000 cannot play songs recorded and saved on the 2400, or 2600. Especially since all 3 are related

The 7000 can play all of the above mentioned KN Boards, just not the newest. Is that the reason?...because the 2400 and 2600 is newer than the 7000, thus the technology is more advanced in the 2400 and 2600?

Larry