The world-famous singer-songwriter had already taken part in many vocal pairings on disc by the time the 'Duets' album arrived in 1993.
A new feature-length Katy Perry special entitled Will You Be My Witness is to premiere on streaming service YouTube Red in October 2017
Joni was the second oldest of the sisters from Philadelphia who will forever be associated with their role in the “Chic sound” of the late 1970s.
