Joni Mitchell's classic, Both Sides Now, was written in the Rittenhouse Square area apartment of Joy Schreiber, aka Joy Fibben, a manager of the Second Fret coffee house, according to many online accounts. But it seems that it was written, in part at least, and inspired by Ms. Mitchell's sitting in this park, watching the clouds go by, see https://mzlevy.wordpress.com/tag/rittenhouse-square/.