Although his music was virtually unknown during his lifetime, Charles Ives is now regarded as one of the most important American composers of the 20th century. His Third Symphony, subtitled “The Camp Meeting,” was completed in 1910 and is a nostalgic glance at an earlier, more straightforward American era. Using dance themes and melodies from popular war songs, Ives imagines an idyllic scene of children playing, ministers preaching, and bells ringing out across the countryside. His Fourth Symphony took 15 years to compose and counts the hymn tunes “Nearer, my God, to Thee” and the work of Nathaniel Hawthorne among its influences. Michael Tilson Thomas leads the San Francisco Symphony Orchestra and Chorus in spectacular benchmark performances of this wonderful but often forthright and challenging music.