Freak Out was my first exposure to Zappa in the 1960s. I got in at the beginning. Hot Rats was the first album where Frank really broke out in a big way with his soloing on Willie the Pimp.
I always thought Apostrophe was yet another milestone in his guitar playing as well as getting public exposure on the radio. Zappa’s guitar work on Nanook rubs it is stellar. He must have had the treble on 15.