The Marina and the Diamonds star recently toured with the 'E.T.' hitmaker and says the support slot allowed her the chance to understand more about huge stage productions.
She said: "I think I relate to Katy because she fought really hard to get where she is right now.
"I chose to do the tour with her because I wanted to analyse everything. The production was amazing - it's one of the biggest tours in the world right now - and I learnt a lot from her."
Marina used to be annoyed at being grouped with other female singers but insists the comparisons are no longer important to her.
She told Stylist magazine: "I don't care anymore about the comparisons but I used to. As a female singer starting out, you'll always be grouped with other women. But once you've established your name as an individual, it doesn't happen."