Songfacts®:

• New Years Day frontwoman Ash Costello wrote "Shut Up" in a day, which is unusually quick for her. She explained: "I was going through some heavy personal stuff, and I was just, 'Don't tell me what I want. Shut up and give it to me.'"
• Costello wrote the song with producers Mitch Marlow and Scott Stevens. She told the British magazine Rock Sound that she showed one of them Kehlani's "CRZY."
  
  "It's so literal, and it's so sassy and powerfully bitchy, and I loved it. He goes, 'Okay - got it. I'm feeling this.'"
• "Shut Up" was co-written by Against The Current frontwoman Chrissy Costanza. It marked the first ever song that Chrissy has written on away from Against The Current.
• The song's bloody music video directed by Galileo Mondol (Raging Nation Films), stars Sirius XM's Jose Mangin. It is an homage to the 2000 Christian Bale-starring film American Psycho, and features the original ax from the movie.
  
  "When we recorded the song 'Shut Up,' I knew right then and there, on that day, straight away, what I wanted to do if we were ever to make a music video for it," stated Costello. "It came to me immediately. So when the time came and 'Shut Up' was chosen for a music video, I was thrilled because it meant that I'd get to make my vision come to life, which was to recreate one of my favorite horror movies of all time, American Psycho."