This week Retrofit is an urbane soundtrack called Bright Lights Big City. For starters, that's a great song by blues legend Jimmy Reed. We'll bounce around neighborhoods and genres with contributions from the Black Keys, Marvin Gaye, Lucero and many other citified song originators. Musically speaking, cities are more often metaphors than they are destinations, but join us as Retrofit keeps it on the block. 5 pm Saturday, with an urban renewal Sunday at noon.