This week on A Prairie Home Companion: a special summertime rebroadcast. It's our 4th of July spectacular from Tanglewood, with Gillian Welch & David Rawlings, jazz singer Inga Swearingen, the elusive P.D.Q. Bach (joined by David Dusing), and out from the dim lights of the orchestra's back row come The Existential Bass Quartet. Erica Rhodes is with the Royal Academy of Radio Actors, Calvin Trillin makes a cameo appearance, and Howard Levy is in with the Shoes. Plus, we'll sing the Star Spangled Banner in the Key of G, and the Flying Elvises drop in on Lake Wobegon.