Complex sentence: Madonna has performed the song in two of her tours, first on the 1990 Blond Ambition World Tour, and 14 years later on 2004's Re-Invention World Tour.
Split into simpler sentences: Madonna has performed the song in two of her tours. First on the 1990 Blond Ambition World Tour, and 14 years later on 2004's Re-Invention World Tour.