How is the guitar a symbol?

The guitar Ed Phelps plays in "When We All Get to Heaven" symbolizes memory. Though Ed has not played in over a decade, as soon as he touches the instrument, he is transported into the past. He plays a song from his childhood which floods him with memories of his father and grandfather, with the songs they sang and taught him, with the world he came from. Ed's experience with the guitar compels him into a rare state of self-reflection, which ultimately reconnects him with his true self.