Many Thanks to those who have responded.

Yes, Realtrack in question (1405) does have a Realchart.

Carried out 'Save Song as MIDI ...' but unfortunately the playback 'rests' are still apparent. Concerning comments about the limits of MIDI reproducing a full performance, it made me wonder if the piano's long sustain is confusing the MIDI process and what should be a long sustained note is being interpreted as a much shorter one?

I'm also not clear about viewing Realcharts. Is it the Realchart that can be seen when viewing notation for any particular Realtrack, or is it viewable as a separate entity, or something else entirely?

Should anyone be able to help further, MIDI and MP3 versions of the track are attached. The disappearance of sound is not too subtle and to me resembles extreme 'gating'.

Attached Files (Click to download or enlarge) (Only available when you are logged in)
1405.mid (15.16 KB, 1 downloads)
1405.mp3 (6.31 MB, 1 downloads)