Complex sentence: In 1987, Love sang back-up for U2's cover of "Christmas (Baby Please Come Home)", while in 1990, Cher invited Love and her sister Edna Wright as her background vocalists for the Heart of Stone tour.
Split into simpler sentences: In 1987, Love sang back-up for U2's cover of "Christmas (Baby Please Come Home)". Additionally, in 1990 Cher invited Love and her sister Edna Wright as her background vocalists for the Heart of Stone tour.