Live music in San Antonio benefits greatly by being close to Austin the self proclaimed "live music capital of the world."  they are definitely spoiled - getting regional and national acts wanting to fill out their tour with a date in San Antonio before or after playing Austin.  There are many great, intimate venues booking great music.

In the downtown area, duelling pianos duke it out at both Pat O'Briens and Howl at the Moon, with award-winning singers keep the punters drinking while playing requests. Drink Cocktail Bar, a cocktail lounge just a block away, has a similar request-based piano duo but in smaller and more intimate surroundings Fridays through Sundays. On the river, Waxy O'Connors features live songs by Joe Walmsley every night and draws a loyal following. 

Retox bar is one of San Antonio's oldest live music venues. Retox has live music on the weekends, with various other acts during the week, with no cover and represents a broad spectrum of rock bands. 

Luna is a little more upscale, listening room with a romantic ambiance.  Music tends to be on the jazz side of things, but they book all kinds so check the schedule.

Sam's Burger Joint  books all sorts of music from Punk to Blues to Singer/Songwriters to Swing to Poetry Slam.  They're currently hosting the San Antonio Blues Society's Blues Jam on Thursday nights.  It's hard to beat the full bar, burgers, and eclectic mix of clientele.

There are also several great institutions, aka dance halls.  A quick drive to Helotes about 20 miles north towards Bandera gets you to John T Floores Country Storean authentic Texas dance hall.  The sign outside says, "Willie Nelson Live Every Saturday Nite."  While those days are from a bygone era, you can still see him a few times a year along with the likes of Charlie Robison, Lyle Lovett, Jack Ingram.  About a 30 minute drive up I-35 just past New Braunfels is Gruene Hall.  It's Texas' oldest dance hall and a destination unto itself.  Along with legendary music there's great shopping, restaurants, the Guadalupe River , and a cool music store, Lone Star Music.

They also have some cool Radio stations. They're a great source of information and a fun way to try out new music.  Both often preview artists when they are playing.  In New Braunfels there's KNBT92.1 an Americana station.  Here in town they're blessed with KSYM 90.1, San Antonio College's radio station.  You'll love their Third Coast Music Networkprogram. (They have a great links page too.)

Add other factors in the area like The Kerrville Folk festival, International Accordion Festival, Austin City Limits Festival, SXSW (and Not SXSW) not to mention all of the Conjunto or Houston Rap music that filters its way over here and I don't think you'll find a hipper music scene than San Antonio.

A great source for up-to-date music information is the Express News' Weekender, it's published every Friday and many of the articles are available at their website