The Charlie Daniels band gave one of its early TV performances from its humble stage. So did Willie Nelson. Pete Fountain has spun jazz tunes from here.
Other performers have produced an alchemy of blues, rock, and gospel. The setting: Studio 6B on the sixth floor of a modern building at the University of Texas here.
The show is ''Austin City Limits,'' a very parochial name for a program that over the years has garnered followers spanning from honky-tonk hideaways in Montana to the steamy climes of American Samoa in the South Pacific.
Now in its seventh season, ''Austin City Limits'' is a country music-oriented show filmed locally and shown on PBS. It is, some would argue, one of Texas's more significant contributions to the nation's cultural tableau.
At the very least, the conception and evolution of the progam over the years reflects some of the changes that have occurred in the ''second Nashville,'' as Austin is sometimes called, and in much of the growing Sunbelt.
One of PBS's top 10 programs, with at least 6 million viewers last year over 247 stations, ''Austin City Limits'' is produced by the Southwest Texas Public Broadcasting Council (KLRN in San Antonio and KLRU in Austin).
To many country-music purists, it is a no-frills program that produces quality sounds without too much show biz. Its mix of music, ranging from Texas swing to Bourbon Street jazz, places it somewhere between Barbara Mandrell and the Grand Ole Opry.
The show was conceived in 1975 by Bill Arhos, now its executive producer and vice-president of programming and production for KLRU. A husky man whose eyes close completely when he smiles, which is frequently, Mr. Arhos says the idea was to present country music in an intimate, almost ''picnic style'' setting.
The result is a program in which, at most, two artists perform in an hour. They play to an attentive crowd of Stetson-hatted businessmen and flannel-shirted cowpokes sitting in a tight horseshoe around the stage.
The show's in-depth treatment of music, plus its occasional forays into original sounds, makes it appeal more to serious country followers and less to the prime-time set: It's more Dick Cavett than Johnny Carson.
Almost since the second taping seven years ago, when a local boy named Willie Nelson came on stage to help kick off the series, the program has been on the rise.
Originally, it featured home-grown artists almost exclusively. Austin in the mid-1970s was a hotbed of musical creativity out of which emerged ''progressive country music.'' Willie Nelson, Jerry Jeff Walker, Waylon Jennings, and other noted country artists lived here.
They throated their ballads in funky nightspots like the Split Rail and the Armadillo World Headquarters. The ''Austin sound'' left its stamp on country music worldwide.
Today many of the honky-tonk clubs are gone. Austin still produces its share of country music. But much of the creative tinkering is in other areas. As the city has become more cosmopolitan, jazz, rock, and other sounds have been produced. Country music, too, has become more diverse.
''Progressive country has disappeared as a vital creative force,'' says Archie Green, visiting professor of folklore at the University of Texas here and a leading authority on country music. ''The country music scene of Austin today is a repetition of Nashville. Young creative musicians today are exploring new wave, punk.''
But he adds, ''There's still more musical variety in Austin than in any other city of its size in the country.''
Out of it all some believe Austin may once again stir a new sound. Holdovers from the heyday of ''progressive country'' like Butch Hancock and a few newcomers are still sketching stanzas on napkins here. Mr. Hancock, a singer-songwriter who first began jotting down words while driving tractors for his father in Lubbock, Texas, is not widely known outside Austin.
But some people here think if there is to be a Woody Guthrie of tomorrow, he will be it. Hancock himself hears Austin bubbling with new sounds.
''I think Austin still has an aliveness to it,'' says the reedy-voiced musician, sporting a two-day stubble and a Wild Bill Hickok mustache. ''There is a lot of mixing of music going on right now.''
''Austin City Limits'' has changed too. Today it puts on a smorgasbord of jazz, pop, blues, rythym, and folk. It has also broadened out to use mostly national artists, a sore point among some local musicians. Its performers range from Kris Kristofferson to Chet Atkins to Pete Fountain.
''Very little of the creative music in Austin today is country,'' said Terry Lickona, the wiry-haired producer of the show. ''So more and more as the series evolved we have gone outside of the city for our talent.''
Despite its forays into other sounds, the show's trademark remains country. ''We've been so successful following the country music formula, we'd be foolish to move away from it,'' Mr. Lickona said.
True enough. With country music sweeping the nation like designer jeans, local producers don't expect enthusiasm for the show to subside. Mr. Arhos observes, ''We're seeing more and more FM radio stations moving to country.''