Why does my purchased song from iTunes sound different after an update?

So about a year or two ago i bought a song from back in 1989 so this a song I know well. I recently updated my iPhone 11 to IOS18 but before I did that I hadn’t listened to the song for a bit. When I put it on it sounded as if the lead singer was singing over his original vocals but that’s not all. There are new parts to the song and the rap bridge is gone all together. I assume this is some recent rerelease but I didn’t by that and that’s not the one I want. How can I get back the song I loved growing up. For anyone that’s wondering the song is called

“Spread My Wings” by Troop off original album called “Attitude”. Thanks in advance for any help u might be able to offfer.

[Re-Titled by Moderator]