Complex sentence: The non-musical play "Porgy" opened on Broadway in 1927, eight years before the opera "Porgy and Bess", and was a considerable success--more so at the time than the Gershwin opera.
Split into simpler sentences: The non-musical play "Porgy" opened on Broadway in 1927, eight years before the opera "Porgy and Bess". It was a considerable success--more so at the time than the Gershwin opera.