Are we to assume that Marcel was related to Wanda?

It's only recently that I discovered that Wanda Landowska (whose cousin
named Jerzy Borenstein I knew well many years ago in Paris) had been
friendly with Lev Tolstoy and at the turn of the century would take her
harpsichord to Yasnaya Polyana (by train) to entertain the family with
the music of Bach.

Best wishes to all,

Jacek Nieaeko
Washington DC