I couldn’t have been more eager to hear Riccardo Chailly and the Leipzig Gewandhaus Orchestra on their return visit to Boston, part of an American tour celebrating the 25th anniversary of the “Peaceful Revolution” that began in Leipzig in October 1989 and a month later led to the fall of the Berlin wall. Chailly continues to be one of most significant and enriching conductors of our time, and it was profoundly frustrating that, in January of 2012, heart problems prevented him from making his long overdue BSO debut (conducting, among other things, Stravinsky’s Sacre du printemps). This cancellation also put him out of the running as a possible replacement for James Levine as BSO music director. There was no way the BSO would risk hiring another music director with health problems. And yet, apparently recovered, here he was in Boston.