Listen to Mellow Retreat into Darkness online. Mellow Retreat into Darkness is an Instrumental language song and is sung by Bluebird Sonata. Mellow Retreat into Darkness, from the album 深夜のおしゃれジャズBGM, was released in the year 2024. The duration of the song is 1:38. Download Instrumental songs online from JioSaavn.