Complex sentence: They had not been performing in New Orleans since Katrina hit the city, however, they finally returned to perform there at the New Orleans Jazz & Heritage Festival in 2008, at the closing spot which had been reserved for them for years.
Split into simpler sentences: They had not been performing in New Orleans since Katrina hit the city. However, they finally returned to perform there at the New Orleans Jazz & Heritage Festival in 2008, at the closing spot which had been reserved for them for years.