“Bird Song_R2” was written years ago by Sean Lennon and the beloved Carrie Fisher, but only after her death late last year did Lennon decide to record it. This unmixed demo version features Lennon’s tender vocals—as well as Willow (Smith) lending heart-wrenching harmonies. Lennon says on Soundcloud, “Carrie and I used to stay up ’til dawn chatting and pontificating about life. They were my best moments. Anyway… we wrote a song about staying up too late and hearing the birds sing.” It’s a minimal, yet entirely striking and exquisite tune.