In-A-Gadda-Da-Vida definitely doesn't have a pipe organ. It's a vox or farfisa.
Sounds pretty nice on a church organ though; in high school, I played in the orchestra for honors district graduation at the Crystal Cathedral[1], and the organist would play some riffs during rehearsal.
[1] Now renamed as the Christ Cathedral, I assume it's still amazingly hot and stuffy when the sun comes out, ugh, what a terrible venue. :P
Yup, it seems that was a Vox Continental: https://en.wikipedia.org/wiki/Vox_Continental
Plenty of other stuff if you look for instance: https://www.youtube.com/watch?v=LKVJt39mFUA&list=OLAK5uy_mTE...
Not to mention the tons and tons of secular Classical music, particular from the Baroque era like Händel's organ concertos.