Sia – Flexible Heart (Piano Karaoke)|Instrumental with lyrics ✘ Subscribe & join our community of aiming singers & pro vocalists! (Switch on notifications). ✘ Join our mailing list for free downloads & inspiring resources for vocalists! We enjoy it when you #sing 2piano and share your creations with us! ♫ Download|Stream – links coming quickly … ♫ Lower Secret. ✘ Version Notes ✘. Tempo is 128 bpm. The key is A. ✘ FREQUENTLY ASKED…