Complex sentence: Although Weisgall's Esther was originally commissioned by the San Francisco Opera, the project came to a halt in 1990, and was resurrected by Christopher Keene and New York City Opera for their 50th anniversary celebration.
Split into simpler sentences: Although Weisgall's "Esther" was originally commissioned by the San Francisco Opera, the project came to a halt in 1990. It was resurrected, however, by Christopher Keene and New York City Opera for their 50th anniversary celebration.