As a conductor, keyboardist, and musicologist, Ruben Valenzuela has led Bach Collegium San Diego in local premieres of historically informed performances of the Renaissance, early and high Baroque, and Classical periods. Under Valenzuela's leadership, Bach Collegium San Diego has achieved local, national, and international acclaim, collaborating with many of this country's outstanding musicians specializing in early music. Highlights include a collaboration with TENET in Los Angeles and New York, and performances at the Festival Internacional del Órgano Barroco in Mexico City and the IX Festival Internacional de Música Renacentista y Barroca Misiones de Chiquitos in Bolivia. Valenzuela's performances have been described as "dramatic and vibrant" and "able to unlock the true power of Baroque music" (San Diego Story). In 2012, he was chosen by San Diego Metro Magazine as one of Twenty Men Who Impact San Diego for his longstanding contributions to the greater arts community, including his outstanding work with Bach Collegium San Diego. Valenzuela frequently appears as a guest director and performer with ensembles including USC's Early Music Ensemble, Santa Monica College's Opera Program, and the UC Irvine's Opera Program. Guest appearances in 2017 will include directing Bach Vespers at Holy Trinity Lutheran Church, New York City. 

As a musicologist, Valenzuela has undertaken research at Centro Nacional de Investigación, Documentación e Información Musical, Carlos Chavez (CENEDIM), and most recently at Colegio de San Ignacio de Loyola Vizcaínas and the Archivo del Cabildo of Mexico City Cathedral focusing on the basso continuo in Novo-Hispanic music. In June 2016 Valenzuela presented a paper titled Mexican Religious Iconography (Angel musicians and the Basso Continuo in Mexico City Cathedral) for the Historical Performance Institute of the Jacobs School of Music (Indiana University, Bloomington). Valenzuela holds a PhD in Musicology from Claremont Graduate University, and is Director of Music & Organist at All Souls' Episcopal Church, San Diego (CA).