When I think of Test for Echo, I think of this guy I worked with for a short while who was also a musician, one of the few times I actually worked with someone I could talk music with. We discovered that Rush was a band we both liked, even though I was somewhat out of touch with them at the time, and he was reading the credits on Test for Echo, which included Hammered dulcimer. He asked me where it was, and I had no idea, being not very familiar with TFE. Days later, I'd forgotten about it, and he came and grabbed me over to his cubicle and put his headphones on me. "Found it!" he said, and I heard it, suddenly remembered our conversation, and laughed.
I don't remember now what song it was. It was in the middle of a jam, and just added for texture, but it was really cool.