Our Team

Matthew Robertson, Artistic Director

Click HERE for Matthew's full bio.

Valerie Simonsen, General Manager

This is Valerie Simonsen’s third season working with The Thirteen and is thrilled to continue in her role as General Manager of this world-class vocal ensemble. She has expertise in concert management, personnel management, database management, fundraising, marketing and donor development. 

Valerie is a classically trained soprano where after completing her Bachelor and Master of Music in Vocal Performance at the University of Cincinnati College-Conservatory of Music, she went on to sing with many music festivals and companies such as Aspen Music Festival, Kentucky Opera, Boston Lyric Opera, Opera Boston, Boston Midsummer Opera, Opera Slavica New York, and Chelsea Opera where she gained an intimate knowledge in the inner workings of non-profit musical organizations. 

Moving to the Washington, D.C. area, Valerie still sings as a soloist with Fourth Presbyterian Church in Bethesda.

Molly Sannutti, Marketing & Operations Associate

Molly Sannutti is a project manager at the University of Maryland as well as an active team member of The Thirteen. With an MBA and a degree in music therapy, Molly has applied her passion of music and business in a variety of settings.


She began as a board-certified music therapist serving children and adults throughout Maryland in public schools, children's therapy centers, adult care facilities, and as an independent contractor. She then started her career at the University of Maryland's National Foreign Language Center (NFLC) in 2015. She currently serves at a project manager at the NFLC overseeing a language materials development project.


Molly continues to pursue her own musical endeavors by performing as a soloist, and singing with the Georgetown Chorale in Washington, DC. Molly thoroughly enjoys combining her talents as both an artist and a project manager to help further the business aspirations of the NFLC and The Thirteen.

Gilbert Spencer, Assistant Conductor

Gilbert Spencer is a conductor and baritone specializing in new music and works from the baroque era and earlier. In the greater Washington area, he can be heard singing with the choirs at the Basilica of the National Shrine of the Immaculate Conception and Washington National Cathedral, as well as with other professional ensembles such as Cathedra, The Choir of St. John’s in the Village, The Folger Consort, Chantry, and Third Practice.

As a conductor, he has led world premieres of  works by Jenny Olivia Johnson, Michael Rickelton, Ledah Finck, and Frances Pollock. Additionally, he has prepared choruses for renowned film composer Hans Zimmer, and the Baltimore Symphony Orchestra under Jack Everly. He is the founder and Artistic Director of Bridge, a vocal chamber music collective that specializes in contemporary music.

As a soloist, Gilbert is frequently heard on the concert stage. He has concertized as a soloist with The Folger Consort, REBEL Baroque Ensemble and Owen Burdick, Musica Spira, and Concert Artists of Baltimore with Edward Polochick. Recently he was in residence at the Banff Centre for the Arts and Creativity in Banff, Alberta, where he recorded a new opera by Jenny Olivia Johnson (release tba 2020).

Gilbert is a graduate of Northwestern University, where he worked closely with Donald Nally, Alan Darling, and W. Stephen Smith.