I saw the the tour in support of "The Division Bell" - at Yankee Stadium, and Driven is 100% correct - it was Jon Carin on the vocals at the end of "Hey You." I assume he did it the entire tour, and hence the shows that became "Pulse".

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"David Gilmour can do more with one note than most guitarists can do with the whole fretboard."

Dave Mustaine (Megadeth)