The very first episode of HSMTMTS gave a little shoutout to "Getcha Head in the Game" on a poster behind Nini.
The first episode also revealed that Sharpay Evans' legendary pink locker from High School Musical is still pink. It even looks like it's gotten touched up over the years!
HSMTMTS filmed at the same high school as the original movies, the real East High in Salt Lake City, Utah, where the locker really is pink and is actually used by students.
KayCee Stroh appeared in episode six of HSMTMTS to recreate her famous "Stick to the Status Quo" moves, and she's still got it.
Troy and Gabriella sang into some pretty cool and totally real wireless mics during their first song together at the beginning of HSM, and somebody kept track of them...
Ricky and Nini were then able to use the exact same microphones to sing into each other's eyes in episode seven.
Ryan was almost always caught wearing a fedora of some sort during the HSM movies, and while Lucas Grabeel was technically playing (a dream version of) himself, he didn't let us down when he appeared in episode eight.
In fact, he wore one of Ryan's actual fedoras.
Does Ricky's backpack strap look familiar?
In episode nine, Ricky wore Troy's actual backpack from the first HSM movie.
During a flashback, Miss Jenn gave a shout out to Kenny Ortega, director of all three High School Musical movies.