With Sonia Wieder-Atherton (2003)

The short documentary starts with Wieder-Atherton telling the story of how she came to fall in love; first with music in general, and then with the cello, and goes on tell how she found her specific style, using the music to try and almost form words of communication. It's a delightful and enlightening interview. This is followed by Wieder-Atherton playing 6 short pieces of quite different styles, from the heartbreaking melodies of Schubert and Brahms to Berio's more edgy modern sounds.

Unfortunately the movie With Sonia Wieder-Atherton is not yet available on HBO Max.