Uh....try using Vegas Audio.

Sound Forge can do this very easily. Look under Effects / Pitch / Bend. You can bend pitch and speed together or either separately. You might want to export the audio to Sound Forge, correct it there, then bring it back into Vegas.

Yeah....I agree. Sound Forge is another great tool too use.

Silly me. I never would have thought to look at Sound Forge. Thanks.

Grazie: I know; it would be better to get the song "right" in the first place. But on this particular selection, the solo is stunning, but the choir sags a bit in the last 30 seconds. Unfortunately the accompaniment doesn't, so I have to take a bit of creative license.

I've actually gotten pretty good at using Vegas to "patch" here and there to improve things. Sour high note? Hmmm, they performed that selection in a couple of other venues, let's just take this little slice from there and put it into here, and then blend the edges a bit: presto! No sour note any more! I don't have any experience doing this sort of thing with any other audio editor, but Vegas makes it appear very easy.

I had a kid's choir that consistently sang a high note flat, and was able to correct this thanks to Vegas / Sound Forge.

The funny thing was they had got into a habit of singing flat, and when they practised by singing along with my recorded track, they improved - sort of like using a splint till the leg heals ....

riredale,
My advice from 35 years in the biz -- leave it. Yes, you notice the pitch sag now, listen to it again in six months to determine how objectionable or acceptable it really is -- you will be appeased. The sensitivity you experience now will dilute and you will realize that the discomfort you feel was not experienced by the audience -- or if it was, the performance is not worth resurrecting.
my

My experience tells me: Use Sound Forge.
Make sure you have a detailed picture of where they drop and how they keep up between drops. Some inexperienced choirs may drop gradually for a long stretch, but a good choir will drop at difficult passages or awkward intervals. Only absolutely top choirs keep pitch throughout.

I once corrected a singer who hit very low on a high note. First I corrected that note but wasn't happy. I discovered that she actually dropped a little just before that note When I corrected at that point and left the high note alone, even though the correction then was much smaller than how much off the high note was, everything sounded right afterwards. So if you must correct, make sure you find the disease and not just the symptoms.

A choir or a solo singer will mosten often drop at a place and in such a way that most ears in the audience find it natural and in fact don't notice. That's why it is so important (if you must) to correct at the point where the problem begins and not neccessarily where you first notice it. Then a small correction can make it all pass unnoticed.
Tor