Complex sentence: Upon returning to Philadelphia Lee worked as a second grade school teacher and bartender in live music venues such as Philidelphia's Tin Angel where he appeared on the bill with Mose Allison.
Split into simpler sentences: Upon returning to Philadelphia Lee held jobs as a second grade school teacher. He also worked as a bartender in live music venues such as Philidelphia's Tin Angel where he had the chance to open for Mose Allison.