@pghsymphony File under audience engagement...unless you are sitting next to someone tone deaf. At the end of its concerts of opera music in early March at Heinz Hall, the PSO will ask the audience so sing-along when it plays the "Anvil Chorus” (from Verdi’s "Il Trovatore" -- you know it). They are hoping that patrons will come before the concert to practice. We will see. In any case, I am for the PSO trying anything new, and there are a few new tidbits in its upcoming season, which we announce this weekend.