At the Village Voice's Michael Musto's blog, La Daily Musto, he recently did a post about these YouTube postings of musical scenes from Gypsy. Seems Rosalind Russell singing was artfully dubbed by Lisa Kirk in the released version, although Roz always swore it was her own voice.
As Musto writes: At the end of each phrase, Roz veers off like Halle Berry at the wheel and sounds like she couldn't hit a note with a baseball bat. Supposedly, Merman got ahold of these recordings and played them at parties to make herself feel better about not getting the movie.
For fans of Jonathan and Darlene Edwards, here is the real thing.