Sunday pre-concert downtown dinner recommendation.
In the Downtown core, Nobuo at Teeter House and Hanny's are both good choices that are open Sundays and located near the major concert venues (USAC, Comerica, & Orpheum). The former is modeled after a Japanese izakaya and can be enjoyed as place for casual shared dishes and drinks or a bit more formally via a four-course tasting dinner. The latter is an upscale bar with good sandwiches, salads, and & thin crust pizzas. I like District, too.
Nobuo at Teeter House
622 E Adams St, Phoenix, AZ 85004
Sundays are tough Downtown. Your best bet for that area might be District. I've never been there, but I know it has its fans. The only other sort-of-nearby Sunday options I can think of are farther north in Midtown (e.g., Durant's, Gallo Blanco).
2611 North Central Avenue, Phoenix, AZ 85004
District: American Kitchen and Wine Bar
320 N 3rd St, Phoenix, AZ 85004
Gallo Blanco Cafe
401 W Clarendon Avenue, Phoenix, AZ 85013