Jon Bon Jovi is calling on fans to enter a new contest in which they sing Bon Jovi‘s new song, “Limitless.” The catch is — they don’t know how the song goes. Fans can use their mobile devices and head to SingBonJovi.com, check out the lyrics and sing along to the song’s backing track, which doesn’t have a top melody, meaning the poster needs to make up the melody for themselves.

Ultimate Classic Rock explained: “Posting the video to Instagram Stories with the hashtag #SingBonJoviContest automatically enters the recording into a contest, with the best versions shared on the band’s Instagram feed. The winner — which the band will determine and announce when they release the whole single — will get to sing ‘Limitless’ on stage with Bon Jovi during their upcoming summer tour with Bryan Adams.”

Bon Jovi and Bryan Adams will rock the United Center on July 21st.