premise: Unison (Celine Dion album) is unreleased.
hypothesis: Unison is the 15th studio album by Canadian singer Celine Dion and her first studio album recorded in English . The album was originally released on 2 April 1990 by Columbia Records . Upon release , the album received generally positive reviews from music critics , who complimented Dion 's voice and technique , as well as the album 's content .