The death of the Austin bombing suspect did little to tamp down concerns of racial bias in the media coverage of his attacks.
The 25-minute recording was discovered by police after a search of the bomber's body.
Many of the attacks occurred during South by Southwest, when much of the music and movie world descends on Austin.
Austin Police Chief Brian Manley said officers could not "ignore the fact that the three victims...were all people of color."
Police are investigating whether there is a link between the first explosion on Monday and another explosion on March 2 that killed a 39-year-old man.
The first night and full day of music in Austin has been refreshingly focused on rising talent.