SOLVED. Boy in high school no longer visible to anyone around him [s]

[[deleted user]]

Hi all. I'm looking for a book I read as a kid in the 80s; I'm not sure when it was published, but I'm guessing it was not too old at the time. The plot is, a boy in high school realizes more and more that people are ignoring him. This escalates until he realizes that no one can see him at all. If I remember right, the world looks gray to him at this point. After days of trying to get people to notice him and talk to him and failing, he finally meets a girl who DOES notice and talk with him, and they become friends. He records his story onto an audio tape. In the last chapter, he explains that he found this audio tape, but doesn't remember anything about this experience. However, the girl he became friends with liked to sing, and at the end of his first audio, he hears her voice, singing.

I was fascinated by this book, and I've been trying to find it for years. Please help if you can! :)

[Diana]

Is it Displaced Person by Lee Harding?

[Cheryl]

I don't imagine it's Things Not Seen or either of the following in that series by Andrew Clements...

[Andy]

Diana wrote: "Is it Displaced Person by Lee Harding?"

That's just what I was thinking.

[[deleted user]]

You guys are AWESOME. I am pretty sure that is DISPLACED PERSON. Thank you so much. :)