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 workers, who are attempting to join IATSE, say the streamer declined their request for voluntary recognition.
The contract covers employees at Secretly Group companies including Secretly Canadian, Dead Oceans and Jagjaguwar.
The audio giant is set to cancel a total of 11 shows from the in-house studios — 10 of which are expected to wrap up next month.
