Louis Armstrong didn’t invent jazz. But he did things with his trumpet and with the genre that nobody had ever done before. His life and career spanned decades that saw changes to the music and to America. And even as he remained the face of both (jazz and America) for millions around the world, he struggled with those changes as a man and as an artist. The play Satchmo at the Waldorf takes us into “Pops’”dressing room as he looks back on his life. We talk to the playwright and Armstrong biographer Terry Teachout and actor Barry Shabaka Henley, who stars in the new Court Theater production.