James Levine is taking over the Boston Symphony next season. And he’s taking the orchestra in a direction it hasn’t been. “What is new in Levine’s programming for the orchestra is an emphasis on the whole of the 20th century, not just the first third. Stravinsky, Schoenberg, and Bartok appear, as they have for decades — but so do midcentury figures as diverse as Gershwin and Messiaen, and such late-century masters as Ligeti, Lutoslawski, and Elliott Carter. The 21st century is represented on Levine’s programs by new works from Milton Babbitt, Charles Wuorinen, and Boston’s John Harbison.”