Concerto pour Lady H

The answer is "No" the actors are not playing the piano. The most telling clue is the hands are located in the wrong registers relative to the music when you see them playing. The close ups show the hands of at least two others who knows how to play the pieces, but the effort expended does not match the soundtrack. If you want to see a better match of actor, stand-in player, and musical dubbing, go see The Seventh Veil, if you can find it on a movie channel.

Otherwise, this is a fairly standard TV movie of a nearly burned out artist who finds a protégé and some emotional fulfillment in a talented young man, Steven.

I guess this was a weeper of the week back in the heyday of 1970's TV movies. Lots of chances to exercise and practice acting, but not enough time to fully develop the story or characters.