The makers of Joker came under a lot of criticism for including this song in the movie. But don’t be misled; these songs were written by Mike Leander (not by Paul Gadd aka Gary Glitter) and they were performed by a group of excellent session musicians who went on to be known as “The Glitter Band”. The Joker movie producers were trying to expose the unfair pain that has been inflicted on innocent musicians.
The frontman, the child abuser Paul Gadd, did not write this material he just fronted it. The session musicians have suffered associated shame, professional ignominy and even poverty because of Gadd. Gadd was and is a monster, but the music was not written by him. He was just the overweight panto act who fronted it.
Gadd (Gary Glitter) receives zero royalties for this music.
So enjoy the musicianship of the people who created it. If you can.