Three 20th century composers riff on the styles exemplified by Bach and Mozart in the opening program. Stravinsky’s “Dumbarton Oaks” evokes Bach’s Brandenburg Concerto No. 3, while Prokofiev channeled Mozart and Haydn in structuring his lovely “Classical Symphony.” Ravel orchestrated his suite for small orchestra titled Le Tombeau de Couperin in a baroque style, delivering a surprisingly light-hearted memorial for friends lost in World War I.