Recently, and to the annoyance of many, the famous 9:30 club changed from to, allegedly because they offer the 9:30 club a larger cut. However, they have very few retail locations. If you want a ticket, be prepared to either go to the box office, or wait for one in the mail, unless you happen to have an Olsson's Books & Records nearby (which unless you live in DC, you likely do not).

Tangentially: Though the 9:30 club does not have a babysitting area, it is open to all ages. This does not mean that it would be suitable for all ages to come alone. However it is a very safe environment, in my experience, as I have been visiting it ever since my early teens.

Alcohol, however, is not easy to obtain, much less keep, for a minor. Virtually everyone who has been to the 9:30 club on multiple occasions has seen someone kicked out for some reason or another, usually involving drinking without proper ID. Smoking is allowed, as is expected of any club in DC which does not have carpets or stadium seats (or ushers).

Though the 9:30 club does not play shows of the same obscurity as the Black Cat or other indie clubs in DC, I believe Wilco is playing tonight, and the Mooney Suzuki is playing soon. Blues Traveller plays later this month. It does have some degree of variety where that's concerned, then, as you can see, ranging from indie-commonplace to played-SNL-8-years-ago.