Key changes in the world of Rock!!!!!!!!

When I listen to many older rock bands like queen, GNR, I notice that the music can sometimes change two or three times in the middle of the song like going through gears almost, its the same note played in a different key so that they sound ascending, or descending. I noticed this is a brilliant compostiotional tool/cheap trick whatever your perepective, but I would love to get a handle on how to choose key changes that work musically, rather than picking a random key and hoping for the best, where would I find what keys should work in terms of the key I start with?

do u mean the cycle of fifths? lol

actually since i last posted here there was interesting thing i learned. From a couple of aerosmith songs as a writing tool i noticed sometimes they will start a song in a minor pentatonic key, shift back 1 semitone, then choose to switch to the major pentatonic key from that particular scale for the guts of the song, then build a bridge from the minor key based on the root of the chosen pentatonic, eg cmaj scale to cmin. As a writing tool u can then move up or down based on the 4th or 5th or u can drop a semitone and go through the same process as you start from. I was messing about the other night after palying the song crazy, and this is what i heard in the structure. If you look to how alot of blues players mix maj and min pentatonic and and chromatic playing this makes alot of sense and has certainly opened alot of doors all of a sudden to me. Not everyone will understand this process, it has taken me eight years, and will probably take another few years before i find exciting ways of executing this knowledge. But maybe it will help someone find another interesting way of musical structure.

Originally Posted by: moody_fa_looniedo u mean the cycle of fifths? lol

Same thing.

to figure out what they do you prolly wanna look up some theory. look up cadences and transposition, you'll defenitely figure out whats goin on.