Avril Lavigne was (and still is) the queen of 2000s Canadian pop music. While she's come a long way from the days of "Complicated," Lavigne is still rocking hard and giving great performances for her fans. Sometimes, she even stars as the special guest on stage. On October 25, Avril Lavigne joined Halsey onstage to sing Lavigne's hit "Girlfriend."\nThe incredible performance took place at Halsey's Halloween party, which had guests dressing up as rock stars from the 60s, 70s, 80s, and 90s. The hostess took the stage in a Marilyn Manson costume, while Lavigne was rocking a vintage Madonna look.\nHalsey's party wasn't just for the rich and famous. Fans were allowed to attend the party for free. However, admission did come with the condition of a mandatory donation to Los Angeles-based charity My Friend's Place, which provides assistance to homeless youth.\nAvril Lavigne has still been going strong with her music career, despite struggling with Lyme disease and going through a divorce from Chad Kroeger of Nickelback. A conspiracy theory was also floating around that the real Avril had died and been replaced by an impersonator.\nHalsey herself also went through a break up early in 2019 when she split from G-Eazy. However, rather than working through her breakup on social media, she instead chose to channel her feelings through her music.\nAt the Halloween party, Halsey had been performing a set for guests at the party and brought Lavigne out as a surprise, and the audience seemed to love it, especially considering how many excited tweets there were about the duet.\nI can’t believe I got to witness Halsey and Avril Lavigne singing “Girlfriend” in the year 2019 !!!! ICONIC pic.twitter.com/f1dIHOunR4— crystal (@iwanturmidnight) October 26, 2019\n"I can’t believe I got to witness Halsey and Avril Lavigne singing “Girlfriend” in the year 2019 !!!! ICONIC," wrote @iwanturmidnight.\n"THIS IS THE MOST ICONIC THING IVE EVER SEEN," wrote @iammadz93.\nTHIS IS THE MOST ICONIC THING IVE EVER SEEN pic.twitter.com/ZHLU4GqBkX— 𝙈𝙖𝙙𝙯⋆ 🍊 (@iammadz93) October 26, 2019\nhalsey threw another sick halloween partyhalsey dressed up as marilyn mansonhalsey performed girlfriend with avril lavignehalsey performed her biggest hitshalsey looks like she’s happytonight was PERFECT— RUBY!!! (@17MINUTESX) October 26, 2019\nIn case you needed it, here’s Halsey, Avril Lavigne AND Jack Barakat in the same 10 seconds pic.twitter.com/xFqQKH7UjN— Lauren ⧖⟠ (@hourglassIove) October 26, 2019\navril lavigne and halsey singing girlfriend live. that's it. that's the fucking tweet.pic.twitter.com/Lgt2rik1kO— ray 6 (@rayloveaffair) October 26, 2019\nHalsey and Avril Lavigne just won Halloween pic.twitter.com/u1ERlm9sD9— Lauren ⧖⟠ (@hourglassIove) October 26, 2019\nmy mom and I used to jam out to girlfriend when I was 7 years old I can’t even tell you how happy I was to see videos of halsey performing that with avril lavigne— el 🍊 (@ellieliima) October 26, 2019\nHALSEY AND AVRIL SINGING GIRLFRIEND IS EVERYTHING pic.twitter.com/oe2MF3D7DQ— staci (@needydemetrias) October 26, 2019\nHalsey and avril lavigne performing girlfriend together OMG my emo heart is so full pic.twitter.com/mHvvvldnrj— sabrina 💎 (@tealambition) October 26, 2019\nWhether people made it to the party or not, at least they got to witness the iconic pop performance through some clips on Twitter, even if it's not really the same as being there.\nThere are stories everywhere. If you spot a newsworthy event in your city, send us a message, photo, or video @NarcityCanada on Twitter and Instagram.