[3] The family moved to Los Angeles when Sonia Marie was four, and she grew up in Echo Park.
[4] She studied piano and organ at California State University, Los Angeles, and graduated in 1984.
She attended workshops of the American Symphony Orchestra League, under conductors such as Maurice Abravanel, Pierre Boulez, Zubin Mehta and André Previn.
[4] De León started the Santa Cecilia Orchestra in 1992, using money of her own.
[4] It performs both mainstream classical repertoire and works by Latin American composers such as Daniel Catán and Silvestre Revueltas.