80s/90s Sci-Fi TV/movie where a man gains the ability to have his wishes granted whilst in a record store

I recall the main, male, character being in a record store and he somehow gains the ability to have his desires granted. At first he wanted to meet a pop star, but the end of the show/TV has him becoming so obsessed with her that he absorbs her and becomes her instead. The ending scene was him going out on stage as her to perform.

The TV show/movie had to have been in the late 80s or very early 90s when records were still a thing.