Tune in tonight at 7 as the Los Angeles Philharmonic and music director Gustavo Dudamel tread where few orchestras dare: they perform a Bach cantata ("Eternity, O Word of Thunder," BWV 60). Also on the program is Felix Mendelssohn's Bach-inspired "Reformation" Symphony, Moravian composer Leos Janacek's Sinfonietta, and Mozart's Violin Concerto no. 3,with soloist Martin Chalfour.