Nothing quite takes me back to my youth like hearing Elton John’s Philadelphia Freedom on the radio. I immediately picture Mr. Flaten’s 4th grade classroom. I think of how much I liked that song and I didn’t even really know what it meant. It seemed kind of heroic to me. And I’m a sucker for strings. With July 4th weekend upon us and an opportunity to celebrate American independence and the birthplace of the United States, here are three Philadelphia-based…