A visit to the countryside and a pleasant, babbling brook. A “merry gathering” of friends and neighbors. A sudden downpour and, finally, feelings of “thanks to the Deity.” This is the path Beethoven charts through his Sixth Symphony, titled “Pastoral” after its idyllic country setting; listen for birdsong, thunder, and the call of the shepherds. Music Director Laureate Edo de Waart returns to conduct this icon. In the first half, MSO Principal Cello Susan Babini performs Elgar’s poignant Cello Concerto.