Boston Baroque’s X-tet presents a concert at 7:30 pm in the Performance Hall and streaming. Drawing membership from Boston Baroque’s world-renowned orchestra roster, the X-tet is the organization’s first-ever period string chamber ensemble. Core members of the X-tet include GRAMMY-nominated concertmaster Christina Day Martinson, assistant concertmaster Jesse Irons, and principal players Sarah Darling, violin, Jason Fisher, viola, and Michael Unterman, cello. Their program will include a pair of violn duests by Gliere and LeClair, a Beethoven Duet with Two Obligato Eyeglasses for viola and cello, and Haydn’s String Quartet in D major, Op. 20, No. 4.