In one evening, experience early-career and late-career approaches to the symphony. Written at age 15, Mendelssohn’s Symphony No. 1 surges with youthful energy, but its poetic slow movement belies the composer’s age. Brahms’s final symphony’s grand architecture is built on the foundation of a series of simple opening motifs that ascend to a stunning final movement: an epic passacaglia (variations over a repeating bass theme) that builds to a cataclysmic climax.