A broadcast of Alexandroff's Fourth Sonata has now been posted.
Once again the timing has been fiddly - in some places it has been necessary to make adjustments with a precision of one twentieth of a second.
Also I find that when the score is displayed the detail of the structural analysis in the lower part of the screen flashes past far too fast to be useful, so I will not use this method again. It would be better to have the analysis in a separate document - or perhaps a separate video track, so that the user could press a button to switch between views.
Again the music comes from a local broadcast around the year 2000, and again I am afraid I do not know who the pianist is - but he is certainly a fine player and follows the composer's directions very effectively.