Complex sentence: The concert, Selena ¡VIVE!, was held at the Reliant Stadium in Houston, Texas.The event not only sold out, but it became the highest-rated and most viewed Spanish-language TV special ever.
Split into simpler sentences: The concert, Selena ¡VIVE!, was held at the Reliant Stadium in Houston, Texas. Not only did the event sell out, it became the highest rated and most viewed Spanish-language TV special ever.