In addition, there were many, many Broadway musicals adapted from movie non-musicals pre-1969. Off the top of my head, Wonderful Town, Silk Stockings, Mame and Promises Promises were hits. Donnybrook, Hazel Flagg, Darling of the Day, Illya Darling, and Shangdi La were flops.
The films for Wonderful Town, Silk Stockings, Mame, Donnybrook and Shangri-La were all adaptations of previously published stories/novels. Darling of the Day was a novel and a play first, but never a film. My Sister Eileen went through three different adaptations before Wonderful Town premiered on Broadway and then two years later, was produced as yet another adaptation as a musical film with a different book and a score by Jule Styne. After that, it was adapted as a TV series, but only ran one season.
"What can you expect from a bunch of seitan worshippers?" - Reginald Tresilian