The album also features Carey's Daydream World Tour concert at the Tokyo Dome, recorded in March 1996, which includes live renditions from her hits, including " Emotions", " Fantasy", " One Sweet Day", " Vision of Love", " Hero", " All I Want for Christmas Is You", among others. The album consists of a 15-track collection of unreleased songs, B-sides, demos and live performances. But they're songs that have previously not been released."
"Basically, I found stuff in my vault that I had either started to work on a long time ago and never released or that I wanted to finish mixing or do whatever. Carey stated on Good Morning America that, To celebrate and promote the 30th anniversary of her self-titled debut studio album, Mariah Carey and her memoir The Meaning of Mariah Carey, Carey announced the release of her eighth compilation album. "This year, been taking something of a victory lap with a celebration she’s calling "MC30", opening the vaults on never-before-seen video footage and an album of unreleased songs and demos called The Rarities, and she’s finally put all that legendary shade to paper with a memoir, The Meaning of Mariah Carey."