On the old Katy Perry Forum we had a huge list of every song Katy had ever sung and/or written. Although it was started by another member I took over updating and maintaining that list around the time Prism was released. It was so large it took up several forum posts.
After KPF closed I started a new site and put the entire list on there.
https://www.katycatsmusiclist.com/introduction.html
Feel free to take a look at the list and refer to it whenever you want.
Remember, there’s much more to Katy’s music than One of the Boys, Teenage Dream, Prism and Witness. The lists cover all of Katy music. Officially released albums and singles, acoustic and live singles, unreleased albums and songs, unrecorded songs, live covers and collaborations and more are included.
Feel free to discuss, contribute and criticize here if you wish.
NOTE: This thread replaces the other one which was deleted.