On Garrett Capps’ “San Antone,” the cagey songwriter pins down the Alamo City’s musical culture with verve and an insider’s knowledge. “I found myself down a deep, dark road / empty pockets and a wayward soul / then I heard somethin’ on the radio / sounded like San Antone. / It had deep blues roots, and a Vox organ / a groovy shaker, and a Fender tone / it said ‘she’s about a mover’ and I was gone / gone home to San Antone.”