Freeman was a long-standing supporter of contemporary music, with grants and commissions to various American composers early in their careers.

[2] The composers she assisted include Lou Harrison, John Cage, La Monte Young, Christopher Rouse,[3] Philip Glass, Steve Reich, John Adams, Anders Hillborg, Pierre Boulez, Harrison Birtwistle, Virgil Thomson, Helmut Lachenmann, and Kaija Saariaho.

The American gamelan Si Betty, built by Harrison and William Colvig in 1979, was named for Freeman.

Bequeathed by Harrison to long-time collaborator and composer Jody Diamond, it has been housed at Harvard University since 2007.

[4] Freeman financed a 1973 documentary film about the composer and instrument builder Harry Partch, The Dreamer That Remains.