Identify noise in Carpenters' "Yesterday Once More"

For @HGN2001 or anybody else, does this help?

Here's a clip from the 1991 remix: https://app.box.com/s/ag1xlvxhi81nu4jxuw9m6e8lkhdr5phy

That's 10 seconds right around the problem spot that Harry mentions in his OP. The same ten seconds play 4 times. The first and third time are "as is," the other times are fed through a mid-side decoder, and this is just the "side" component, which contains some of the airy-er, fluffy-er stuff.