Listen to Soft Keys for Slumber online. Soft Keys for Slumber is an Unknown language song and is sung by 963 Hz Solfeggio Tones, Sleep Music for You and Sleep Music 101. Soft Keys for Slumber, from the album Lofi Sleep Rhythms: Melodies for Soothing Nights, was released in the year 2025. The duration of the song is 2:35. Download Unknown songs online from JioSaavn.