The Yamaha AN1x Synthesizer mailing list

Yes, the message is Active sense....almost all Yamaha keyboards send
this message. Its part of the MIDI spec and is in general a good idea.
(If you check the AN1x MIDI implementation chart you will see that the
message is both transmitted and received by the device)

No, there is no way to turn it off on the An1x (or at least I don't know
of any way to disable it ;-(

The message is designed for live performance situations, to avoid hung
notes. For example if someone kicks the MIDI lead out, then the
receiving device will turn off any sounding notes.

All sequencers that I am aware of simply consume the message (they do
not store it or forward it). 

Regards

Gary Gregson

Email:gary@...
http://www.yme.co.uk/yme