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 currently serves on the Board of Trustees of Early Music America.
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.
Andrew Nguyen, Artistic & General Operations Manager
Andrew Nguyen is an arts administrator, clarinetist, and educator whose work is grounded in the belief that the care taken with musicians offstage is inseparable from what audiences hear onstage. Andrew joins The Thirteen from the Peabody Institute of the Johns Hopkins University, where he completed his Master of Music in Clarinet Performance while spending two years as an ensemble management intern. In that role he served as an administrative liaison between conductors, faculty, and student musicians, and maintained production calendars, rosters, and personnel records for hundreds of singers and instrumentalists across the conservatory's large ensembles and chamber groups.
During the summer of 2025, Andrew served as Senior Artistic Operations Assistant at the National Orchestral Institute + Festival, hosted by the University of Maryland's Clarice Smith Performing Arts Center. There he helped train and supervise a team of operations assistants and manage logistics and hospitality for more than eighty guest artists, conductors, and fellows. Earlier, at the Bob Cole Conservatory of Music, he managed communications, stage plots, and the music library for three wind ensembles. He has taught woodwinds with the Philharmonic Society of Orange County's youth symphony and in private studios across Southern California.
A clarinetist by training with a particular affinity for the bass clarinet, Andrew has served in various principal roles in his conservatory ensembles and was named a winner of the 2023 Bob Cole Conservatory Concerto Competition. He has studied at the PRISMA Festival in British Columbia; the Zodiac Music Academy and Festival in Nice, France; and the Lawrence Chamber Music Festival in Wisconsin. He holds a Bachelor of Music in Clarinet Performance and Instrumental Music Education from the Bob Cole Conservatory of Music at California State University, Long Beach. His principal teachers include Alexander Fiterstein, Helen Goode-Castro, and Mathieu Girardet.
A recent transplant from Southern California, Andrew lives in Washington, D.C. In his free time, you can find him roasting and brewing his own coffee, tending his aquariums, lifting weights, or exploring nature.