Isabel Thiroux

Interim Executive Director


Isabel Thiroux has been with the American Youth Symphony since she first joined the viola section in 2001. After seven years in the orchestra, she “graduated” to working in the office, becoming Orchestra Manager in 2010 and Director of Orchestra Operations in 2015.

Ms. Thiroux studied viola at CSU, Long Beach with LA Philharmonic violist John Hayhurst and maintains an active career as a freelance violist performing regularly around the Los Angeles area.

Nicolas Bejarano

Development Director


Nicolas Bejarano was hired in 2022 after serving as the Director of Development for Long Beach Opera. He is also a trumpet player, and a former AYS orchestra member (2017–2020). He specializes in contemporary and new music and has appeared with the Los Angeles Philharmonic, WildUP, Monday Evening Concerts’ ECHOI Ensemble, The Industry Productions, the Ojai Festival Orchestra, and the Martha Graham Dance Company to name a few. He has also had the pleasure of working on projects for composers LaMonte Young, John Adams, David Rosenboom, Gabriella Smith, Ellen Reid, Chris Bowers, Nico Muhly, and Frederic Rzewsky to name a few. Bejarano holds a B.Mus. from McGill University and a M.F.A. from the California Institute of the Arts.

Katie Speer

Community Engagement and Marketing Manager


Katie Speer was hired in 2023 after serving as the Marketing and Patron Services Associate at Long Beach Opera. During her career in the performing arts, Katie has been a professional stage manager, company manager, and technician; she has also had the pleasure to perform as a dancer and aerialist with The Walt Disney Company. Katie holds a bachelor’s degree in technical theatre from California State University, Long Beach and is currently working towards her Master of Arts Leadership and Cultural Management degree remotely at Colorado State University.

Tim Kopacz

Operations Specialist


Tim Kopacz is an artist, administrator, and producer at several Los Angeles area non-profit organizations. He is an active educator in the film and TV community, as well as a performer himself. He has degrees from both Boston College and Brown University.

Mark Gutierrez

Community Educator & Share-A-Stand Lead Instructor


Mark Gutierrez is a Los Angeles born upright/electric bassist, vocalist, composer, lyricist, and producer. He has been performing and creating music in the greater Los Angeles area for over ten years with a variety of ensembles, ranging in genre from Latin music, to Jazz, to Classical/Orchestral, to Hip Hop and more. An alumni of the American Youth Symphony, Mark now works with AYS’ Share-a-Stand program to bring advanced music training to students in LAUSD.

Sarah Bunch

Orchestra Management Fellow


Sarah is a violinist based in the LA County area. She joined AYS as a player in 2018 and took on the role of orchestra management fellow in 2021. She is also an active member of another orchestra in the Antelope Valley called West Coast Classical, where she serves on the board of directors, directs one of the beginning strings programs, and sits as concertmaster of their Symphonic Orchestra. Alongside her orchestral responsibilities and freelance work, Sarah is a private violin instructor.