Break-Up: Diana Ross left The Supremes in 1970, but they carried on with new singer Jean Terrell and continued to score hits and tour for a few years. By 1977 things had slowed down considerably and they called it quits.
Reunion: Mary Wilson and Cindy Birdsong briefly put aside their differences with Diana Ross at the 1983 Motown 25th Anniversary Concert. (Founding member Florence Ballard died in 1976.) They performed "Someday We'll Be Together." Three years later, Wilson released her memoir and it was sharply critical of Ross, driving the two even further apart. In 1999 Ross reached out to Wilson and Birdsong about a reunion tour for the following year, exactly 30 years after they had last played a full show together.
Duration: This one went really, really poorly. According to multiple reports, Ross was offered around $15 million, Wilson was offered $2 million and Birdsong $1 million. They asked for more, but were ultimately replaced by two latter-day Supremes who had no history with Ross. This resulted in a flood of negative press, and ticket buyers seemed to have little interest in this "reunion." The tour forged ahead, but was canceled after less than a month.