Guest conductor Michael Francis led a Milwaukee Symphony program Friday of two fascinatingly different symphonies: Leonard Bernstein’s consuming Symphony No. 2 (“The Age of Anxiety”) and Johannes Brahms’ intense, mercurial Symphony No. 1. Pianist Joyce Yang joined the orchestra for the Bernstein, which, despite its title, is a virtuosic concerto for piano and orchestra. Yang juxtaposed fire and delicacy throughout, moving from thunderous power to achingly beautiful, fragile sounds.