The band announced on social media that Jeff Brown had passed away on July 13, 2021 of natural causes related to a medical condition.
Brown was a bass player and had been a member of the band for 12 years.
"Through all of the records, the tough shows and the incredible shows Jeff brought professionalism and passion. He never wavered in his stance to bring his absolute best," the band said.
An official obituary says Brown was 42 and originally from Camp Hill, Pennsylvania. He had been living in Austin for 15 years.
Brown graduated from Penn State University and is survived by a brother and his parents.