In the last of three appearances with the Boston Symphony Orchestra at the 2012 Tanglewood Festival, Christoph von Dohnányi continued the thread of mid-period Beethoven with the Fourth Symphony, which abounds in a similar spirit of disciplined anarchy as Strauss’s dazzling rondo on the life of rebel and prankster Till Eulenspiegel. At the concert’s centre, serene order reigned in Mozart’s A major piano concerto K488.