Greetings,
I have a blog that tries to find influnences of pop music on game music. I recently posted two entries one of a song from Gradius, one from R-Type Final, in case you're interested:
R-Type Final: https://www.destructoid.com/--655401.phtml#post
Gradius Gaiden: https://www.destructoid.com/--654971.phtml#post