The University of Texas at Austin’s Butler School of Music has unveiled its 2023-24 season. Here is a rundown of the vocal performances. The season opens with a concert starring soprano Leah Crocetto. The showcase, which will be conducted by Douglas Kinney Frost, will include the world premiere of Clarice Assad’s “Baião n’ Blues,” Barber’s “Knoxville: Summer of 1915, and Brahms’ {…}