The Santa Fe Plaza is the heart of the city and I recommend spending as much time as possible on the Plaza during your visit. Not only is the Plaza the best people watching spot in the entire town, there is a bandstand in the Plaza which holds free summer music concerts.
Always check to see if there is a Bandstand concert during your visit. The free concerts are fun and allow you to mingle with the locals who attend these free concerts at their beloved Plaza in droves.
A fun time is guaranteed and it is free. There are food trucks and food stands for munchies during the concert.
Check the summer concert calendar at santafebandstand.org