The folk-rock duo — who've been filling venues and inspiring singalongs since the late '80s — are performing tonight at San Francisco's most iconic movie palace, and honestly, it just makes sense. The Castro Theatre has been a cultural anchor for the neighborhood for a century, and the Indigo Girls have been a cultural anchor for, well, a whole lot of people who live in that neighborhood.

For those keeping score at home, Another Planet Entertainment has been running the Castro's live programming since taking over operations, and bookings like this are exactly what the venue needs to stay relevant and solvent. Love them or not, APE has been putting bodies in those ornate seats, and a financially sustainable Castro Theatre is better than a shuttered one — no matter how many preservation debates rage on.

This is worth celebrating for a simple reason: private enterprise keeping a historic venue alive through smart programming, without a dime of public subsidy propping it up. No ballot measure needed. No supervisorial grandstanding. Just a promoter booking acts that people actually want to see, in a room people actually want to sit in.

The Indigo Girls have sold over 15 million records and earned a Grammy, so expect a packed house. If you didn't grab tickets already, you're probably out of luck — but you can always grab a drink at one of the Castro's bars and soak in the neighborhood energy that a good show brings.

Say what you will about the changing face of San Francisco nightlife and entertainment — tonight, the Castro Theatre is doing exactly what it should be doing: hosting great artists, drawing a crowd, and keeping the lights on the old-fashioned way.