The definition of a musical failing or "flopping" is blurred these days, with the involvement of not-for-profit theaters. If a show just runs its New York off-Bway limited engagement, clearly intending to move if the reviews warrant it, then gets disappointing reviews, and simply doesn't move to Broadway, does that count for our discussion? If so, I'd put several songs from Lippa's WILD PARTY, quite a large number of songs from Ahrens and Flaherty's MAN OF NO IMPORTANCE and DESSA ROSE, several from Menken and Spencer's WEIRD ROMANCE, Cook and Fryer's CAPTAINS COURAGEOUS, and naturally Skip's own TIME AND AGAIN score on my list of favorite songs for the TOD.