i have a band for almost every land.
Eden Ahbez's music really sounds like Adventureland to me.
There's a folk group from the 50's called The Easy Riders who's music always reminds me of NOS. The lead member, Terry Gilkyson actually wrote "The Bare Necessities" for The Jungle Book, as well as some other disney tunes, but i've probably mentioned that before.
Although very campy, The sons of the Pioneers sound like the ultimate soundtrack for Frontierland.
For IASW it's The Mamas and the Papas while Jefferson Airplane typically remind me of Alice..
I know i have more but those are all i could think of right now.
It really depends on the trip itself, typically whatever I have stuck in my head. Just recently, it was most of the songs from Grindhouse - specifically Death Proof. I don't remember how many times I said, "This car is 100% death proof, only to get the benefit of it honey, you really need to be sitting in my seat" last Saturday.
"Magic" by Olivia Newton John (from "Xanadu"): takes me back almost three decades when I remember hearing the song played by "Sunshine Balloon" or whatever cover band was arising from the Tomorrowland Terrace stage. I am ascending the SpeedRamp to the Monorail, feeling smelling that delightful mix of chlorine and diesel wafting up from the Submarine lagoon, and seeing so many buckets of the Skyway overhead.