This concert of beloved clarinet trios includes a new work by Joseph Hallman, a prolific young composer based in Philadelphia, which was co-commissioned by UMS as part of the Music Accord commissioning consortium. The performance also includes Beethoven’s playful Clarinet Trio in B-flat and Brahms’s Clarinet Trio, written near the end of his career and prompting a musicologist friend to proclaim that “it is as though the instruments are in love with each other.”