He naturally shared his interests in music with his first wife, Yardena Alotin. Yochanan was a skilled singer and sang for many years with the Rinat choir.
There are several videos of both the chorus and the compositions by Yardena Alotin
You can see YR in the back row, second to the left
(left is from behind)
I have chosen this composition to stress the fact that they shared an interest of learning skill and performance.
He was teaching form in order to give his students the freedom of improvisation.