Please help with installing OS 9 on Power Mac G4

Hi,
I recently purchased a used Power Mac G4/AGP/500Mhz/ computer for the sole purpose of running an audio program that requires OS 9.2 (will not work in OS X classic). The computer was shipped to me with a clean install of OS 10.4.
I read that it was difficult to install OS 9 after X was already installed. Not needing X, I booted from my X install disc and reformatted my hard drive to wipe it clean. I didn't have a copy of 9 yet, but I had 2 different people make copies for me. When I try to boot from the first of the 2 copies I just get a blank light grey screen. Nothing happens, I have to restart to try something else. I looked at the contents of this disc, and everything seemed correct. The other copy a different person sent yields a a flashing diskette and ? on the screen.
Did they both send me bad discs? (They were both mac-guys who seemed knowledgable).
Not sure what to do, my knowledge is pretty limited here however I can follow instructions well.
I'd really appreciate any help, thank you, Jeff

yes i think you should try to zap the pram
(apple logo-option-p-r)this might help