It was the performance heard ’round the world. Or rather, not heard, but played on tape. Almost 20 years after the second most-famous lip synch scandal in modern pop history — shout out to Milli Vanilli — Ashlee Simpson dropped by the Broad Ideas with Rachel Bilson and Olivia Allen podcast this week to relive that moment in 2004 when her Saturday Night Live debut turned into a car-crash viral moment before such things even existed.

“I’ve never talked about or said, but it’s like the other thing is, learning as a woman, when you say no, or as an artist or a human or whatever, that day I said ‘I will not go on, I don’t care. I can’t speak,’” Simpson, 39, told the hosts about the night in Oct. 2004 when she was the musical guest on SNL amid serious vocal issues that caused her to lose her voice before showtime.

After rehearsing the day before, Simpson said she woke up and realized she “couldn’t speak,” because, her doctor told her, she had two nodules on her vocal cords that were “beating against each other.” She explained her dilemma to the SNL team in a handwritten note, but despite telling producers the show could not go on, Simpson said she was asked to perform to pre-recorded vocals. “My band has never practiced this, this is not going to go well,” she said she thought at the time. “I can’t do this.”

Simpson, of course, did perform that night, first coming out to sing the single “Pieces of Me,” which went well. But when she came back to play the title track from her Autobiography album, someone cued up the vocal track from “Pieces” by mistake. Simpson busted out some stilted dance moves and when she was caught with the mic by her side, she and the band looked around confused for several awkward seconds while the singer did a silly shuffle and then walked off stage as the group continued to play the instrumental track and the show cut to commercial. Simpson came back later for the closing credits and said, “My band started playing the wrong song, and I didn’t know what to do, so I thought I’d do a hoedown. I’m sorry. This is live TV. These things happen!”

The mortifying moment taught Simpson the “power of my no,” she told the podcast hosts, as well as “the power of me saying absolutely not… that’s what I would go back and say.” To be sure, Simpson said it was a “humbling” incident for her at a time when she had a No. 1 album on the Billboard 200 chart and a top five single with “Pieces of Me.”

“It was like everything was about to go somewhere and then it was just like, whoa, the humility of not even understanding what grown-ass people would say about you… awful, awful things,” Simpson said of the first, and only, time a musical guest had walked off SNL during a performance. Through that trial-by-fire, though, Simpson said she learned to tune all the noise out and find her strength and move on, while, luckily, also avoiding throat surgery thanks to a vocal coach who “saved my life.”

The clip went so viral at the time, though, that one of the friends who was with Simpson that night — and who joined her on the podcast — said when they visited a New York deli the next day in the midst of the Iraq war “everyone around us was talking about it… it was so surreal and such a ginormous moment.” Though she released two more albums, 2005’s I Am Me and 2008’s Bittersweet World, and starred as Roxie Hart in three different productions of the musical Chicago in 2006, 2009 and 2013, Simpson’s musical career never regained that initial peak following the SNL fiasco.

To this day, Simpson said people still ask her about it and she can’t forget the important lesson she learned that night. “I think having to find at a young age that strength to be like, ‘I am good at this and I will keep going, and I will keep fighting,’” she said, noting that she came back to SNL a second time a year later and she can’t find the video. “I’ve searched and searched for that performance. I was really nervous when I was on there and I can’t find it anywhere,” she said.

Though she’s been off the music radar for years, the singer recently told US that she’s starting to work on the re-release of her debut album and may fill it out with additional tracks. “I’m going to celebrate that album,” she said. “Maybe I’ll go in and redo some of the songs, but I’m definitely going to do a performance around the anniversary.”

Watch Simpson discuss her SNL incident below (beginning at 45:00 mark).