Songfacts®:

• "Tusa" is Colombian slang for the heartache and loneliness a person feels after a lover breaks up with them. Here, Colombian reggaeton singer Karol G croons about getting really sad whenever she hears the song she and her ex used to listen to together.
• Karol G started corresponding with Nicki Minaj on Instagram in the summer of 2019, swapping demos until they decided to collaborate on this one. The Columbian singer-songwriter recalled to Billboard that she sent the Queens rapper the music at 1 p.m. Within seven hours she had the song back with a verse, in which Minaj tells off an ex.
• Minaj surprised Karol G by recording some of her lines in Spanish.
  
  Pero hice todo este llanto por nada
  Ahora soy una chica mala
  
  An English translation is:
  
  But I cried all of that for nothing
  Now I'm a bad girl
• Colombian songwriter Keityn originally wrote the bulk of the track with producer and Karol's frequent collaborator, Ovy On The Drums. Keityn had no plans to make music that day. He was just going to hang out with Ovy, play video games, and eat chicken wings, but fate had other plans. The producer couldn't get a violin melody out of his head, so he asked Keityn to help him write lyrics.
  
  "I swear, in less than half an hour, we had 'Tusa,' from the pre-chorus to the chorus," Keityn told Billboard. "It flowed too well. The muse was in the house that day."
  
  Ovy stored the song in the studio for over a year, but he and Keityn knew it was destined to be a big hit.
• Karol G explained the song title to Billboard: "'Tusa' is when no matter what you know, what they do to you, how much they step on you, how much it hurts, you're entusado [disheartened], because you can't get over it... oh, it's happened so many times to me!"
• Keityn and Ovy On The Drums originally called their tune "La canción (The Song)," a reference to its storyline about the memories that flood back of a past relationship whenever their song plays on the radio. When Karol G agreed to record the song she added her rap, and suggested changing the title to "Tusa."
  
  "Honestly, I didn't like the word," Keityn admitted to Billboard. "It's too local, too Colombian. I simply used it because it rhymed. When Karol told me that was the title, I said, 'No, I don't like that word.' And she said, 'Trust me.'"
• The song peaked at #1 in numerous countries, including Chile, Peru, Spain and Argentina, where it became he longest-running chart-topper, spending 25 weeks at the summit. The previous record holder had been Sech, Ozuna and Anuel AA featuring Darell and Nicky Jam's "Otro Trago," which spent 13 weeks at the Argentine Hot 100's peak position.
• "Tusa" won Song of the Year at the 2021 ASCAP Latin Music Awards.