Complex sentence: The song was intended for Ringo's 1992 "Time Takes Time" album; however, it did not make it onto the album, and therefore remains an intriguing, publicly unheard song.
Split into simpler sentences: The song was intended for Ringo's 1992 "Time Takes Time" album. However it did not make it on the album, and therefore remains an intriguing, publicly unheard song.