Marc Mandel is in charge of the Boston Symphony Orchestra’s (BSO) program book and pre-concert talks, and has taught summertime weekend programs and R&R sessions at Kripalu since 2006. On the BSO staff since 1978, he is the BSO’s principal pre-concert speaker and the originator of BSO 101, a popular, free adult-education music appreciation series that has been offered at Symphony Hall in Boston, at Tanglewood, and in communities throughout the Boston area.