There’s a song in the air and it’s about change. The future is just around the corner… but not quite, not yet. On this week’s broadcast, we’ll ponder the problem of the unknown, with music for Advent, including an atmospheric pharaphrase by Hans-Andre Stamm, a collection of Bach chorale-preludes, and an improvised symphonic movement by Marcel Dupré that he recorded with compelling persuasiveness in his 79th year.