Every decade produces a song that is impossible to avoid and becomes a drunken karaoke favorite. The 80s have a ton of them, but in my personal opinion, the crown has to go to Journey's Don't Stop Believing, which will reliably cause perfectly rational adults to form amateur cover bands at the grocery store. When it comes to 90s songs that have the ability to make people become MK Ultra-style backup singers, two tracks spring to mind: My Heart Will Go On and I Will Always Love You.
Yes, I know that the latter track was originally a Dolly Parton song from the 70s, but the records association with Whitney Huston and The Bodyguard will forever tether it to the 90s. According to AV Club, an audience in Manchester was so overcome with nostalgia that they began to sing along with the track during a musical performance of The Bodyguard.
Per Variety, the Friday night Manchester production of the show actually had to stop down more than once, as a few members of the audience simply wouldn't stop singing along with various songs. (Reportedly drawing cries of "Shut up" from the more restrained voices in the crowd.) But the final straw came at the play's climax, when star Melody Thornton (from The Pussycat Dolls) went for her big showstopper, only to have the show, uh, stop, with her mic cut and house lights brought up due to the unwelcome accompaniment. We're just going to go ahead and quote the Variety story verbatim here about the aftermath, because it's fascinatingly surreal: "Two women were forcibly pulled out of the theater by security, and several police cars arrived to oversee the evacuation of the theater after what patrons on social media described as 'fights in the aisles' and even 'a mini-riot.'"