Lola Brooke and Armani White are also scheduled to perform.
The group of artists launched a petition, signed by more than 400 acts, urging the festival to increase compensation for those set to play.
The band have been announced as the festival's first artist ambassad
The third wave of SXSW performers is a mix of legends, newcomers and everything in between.
The girl group and their æ-counterparts will star in the 20-minute VR experience The post
The artists are among the latest batch of speakers for SXSW, taking place March 10 - 19 in Austin.
"Jannis was a gentle, kind soul, always appreciative of our team helping him to share his art with the world," the musician's label shared in a statement.
The festival is due to return in March The post
The six-day event will have plenty of music to choose from.