Renata Borgatti (1894-1964) was a daughter of a famous Wagnerian tenor. She herself became a great concert pianist at a time when the field was overwhelmingly dominated by men.

In 1920 she was painted by the expatriate American 
Romaine Brooks (1874 - 1970). Brooks was made Croix de la Legion d'Honneur following the Salon de la Societe Nationale des Beaux-Arts that year. 

I'm not exactly sure how this Charcoal sketch  came about but Sargent, an officer of the Legion d'Honneur and a great admirer of music, seems to be following after Brooks' portrait -- at least in part -- trying to capture that strong profile -- which in itself was tribute to Whistler's work:

James Abbot McNeill Whistler

At The Piano
1858-1859
 

Notes:
 

• See the year in review  1920-1921