Go online to the SXSW site and navigate to the music festival section. Take special note of the deadlines for submitting an application. There is a minimal cost for the application.
Complete the application by including information about the act's hometown, size of group and the selected contact. Any information like the bands website or newspaper articles, for example, help communicate the feel and style of the band.
Upload the music, photos and press kits for review by the committee. The recordings are listened to twice or more and then those artists with the highest marks are invited to perform.
Schedule other play dates around the conference to capitalize on the invitation. SXSW encourages this and will also incorporate you into the panel sessions to encourage networking.