Quintanilla was the first woman to conduct the Venezuela Symphony Orchestra on November 18, 1967, premiering her Tres Canciones para Mezzosoprano y Orquesta (Three songs for mezzo-soprano and symphonic orchestra),[1][2] which was awarded the National Music Prize that year. She had previously conducted the choir and orchestra of the Asociación Wolfgang Amadeus Mozart.
She has been active as a pedagogue throughout Venezuela, teaching music theory, harmony, counterpoint, harp, and piano in various conservatories and music schools until her retirement in 1990. From 1985 until 1990, she was the director of the Escuela Nacional de Música Juan Manuel Olivares in Caracas; she has also served as director at the Music Conservatory in MaracayMaracay (1980).
As a composer, she has produced several cantatas and other vocal works. She has also written chamber music and soloist works, especially for the piano, harp,[3] and trumpet.[4] Her music has won over a dozen awards and prizes throughout her career, and she has also been honored with several Orders and Decorations.[5]