The spirit of Brahms hovers over Ronen’s first concert of the 2025-26 season, a program flanked by two of the German icon’s chamber masterpieces: the first violin sonata, in an arrangement for flute and piano, and the so-called “Werther” piano quartet, a tragic piece rooted in the composer’s youthful love for a married woman (any guesses?). The trio for oboe, horn, and piano by Brahms’s friend Heinrich von Herzogenberg, featuring Ronen co-artistic director Jennifer Christen, rounds out the evening.