STAFF
Matthew Robertson, Artistic Director
American conductor Matthew Robertson (b. 1986) is the founder and driving voice of the professional choir and orchestra The Thirteen, which he has led in more than two hundred concerts, two dozen concert tours, nine commercial recordings, and numerous world premieres. Noted for boundary-defying performances that “transfigure the listener” (The Washington Post), for his “incisive tempos and dramatic pacing” (Washington Classical Review) and “flowing lines and dramatic climaxes”(Fanfare Magazine, UK), Robertson’s vision has led to acclaimed performances of a diverse repertoire, often featuring use of staging and multimedia, and to The Thirteen’s winning the Most Creative Programming Award from the Greater Washington Area Choral Music Awards.
Angela Marroy Boerger, Managing Director
Angela Marroy Boerger is an arts administrator, musicologist, and violinist who has spent her career working to build conversations and communities around artmaking—the result of her deeply-held belief that access to an arts-rich life is a fundamental civil right. Angela joins The Thirteen from Arts Every Day in Baltimore, where she was Director of School Programs and Learning and worked with Baltimore City Public Schools to ensure equitable access to the arts for all students in the district. While at Arts Every Day, Angela founded the Baltimore Arts Integration Project, a $2.9 million US Department of Education-funded initiative.
Prior to her work in Baltimore, Angela was the Education Manager at the Metropolitan Opera, where she led the education curriculum and programming for the Met’s HD Live in Schools, an opera education and access program in 38 states across the country for over 16,000 students each year. Angela has also served as Director of Education at Westport Country Playhouse, as a Music Writer for McGraw Hill Education, and as Managing Editor of Bare Opera in New York.
Trained from youth as a violinist, Angela discovered historically-informed performance practice as a violin major at the Shepherd School of Music at Rice University. She holds bachelor’s and master’s degrees from Rice in musicology and medieval studies, and pursued PhD studies in music history at Yale University, writing on Viennese opera at the end of the eighteenth century. Her wide-ranging research interests have included classical and contemporary opera and Lieder to American swing dance music and Duke Ellington.
Angela lives in Maryland with her husband Tim and children Sophie Magdalena and Thaddaeus James, who are aspiring graphic novelists and paleontologists, respectively. In her free time, you can find her on sunny days working in her gardens, and in inclement weather, pursuing a never-ending list of restoration projects in her historic home.
Mary Helen Pryal, Marketing & Operations Coordinator
Mary Helen Pryal is a multi-faceted arts administrator and communicator, driven by a desire to make the arts accessible to all audiences. Her professional experience includes sales and event coordination at Arena Stage, institutional fundraising at the Folger Shakespeare Library, and corporate partnerships at Arena Stage. She holds a Bachelor of Arts in Drama, with a minor in Performing Arts Management, from the Catholic University of America.
Mary Helen lives in Falls Church, Virginia, and in her free time she can be found practicing yoga, reading contemporary plays, and trying new recipes.
Abigail Slate, Artistic Operations Coordinator
Abigail Slate is an arts administrator and production professional whose work centers on supporting artists and organizations through thoughtful operations, logistics, and collaboration.
Abigail brings several years of experience in performing arts administration, production coordination, and venue operations. Prior to joining The Thirteen, she held roles at the Thrasher-Horne Center for the Arts, where she supported programming, marketing, guest services, and large-scale live events, working closely with artists, technicians, and visiting companies. Her professional background also includes collaborating with contractors and small businesses, managing schedules, communications, and operational details across fast-paced performance environments.
She holds a Master’s degree in Entertainment Business, and has built her career around live performance logistics, artist relations, and detail-driven project management. Known for her adaptability, calm under pressure, and collaborative approach, Abigail is drawn to organizations that value both artistic excellence and care for the people who make performances possible.
Originally from Florida, Abigail is new to Arlington, Virginia, and enjoys exploring the region’s arts community, hiking local trails, and spending time with her husband and their two dogs.