What I think I'll need to create is some completely different drum styles. so I guess my questions is whether or not the only way to create the drum parts is by modifying the already existing audio files for drums found within the Audya.

If this is the only way it may be a problem because I don't know how you can modify an audio, unless it'd turn possible to simply transfer complete audio recordings of drums playing to make them the drum part of a style then add different files for variations and fills. That would be great indeed.

I did it once a bit with my Casio by writing the midi for each part on my computer then transferring it to the keyboard but I'm not sure how it works on the Audya, since, again, the drums are not played by midi.

Hi my friends....
So....With Audya you can to make styles with:
1) With Midi sequence ( midi file format 0 ) in a host (like Cubase, Logic, Sonar etc) and with Style Compiler you can to compile a new style and modify in Audya, or Style Compiler with Audio, User_Audio Guitars, Audio, User_audio Drums, etc...
2) onboard in Audya with Pattern Edit and you can to use Audio, User_Audio Drums, also Midi Drums etc....
3) With method AUDIO STYLE MODELING
This is a very easy method to make new style without any Edit but you can to select Audio and Midi Drums and Instruments Loops and Riffs, in all Channels of Style and you can with a Remix, to make a new Style!!!!.... VERY GOOD!!! VERY EASY!!!...
Best Regards.

Sokratis,
it not so easy witrh Style Compiler.What I mean:sometimes Style Compiler dont recognize Pat.file(program show tekst:baad file)and in this case you cant do enithing.I dont know a reason of that kinde behavior.Ather style I can compile or edit with no problem.
I would like to asck you for little help.Haw I can insert more measure betwen two markes in Sonar8 program?
Style Compiler can maket a blank Midi file with all markers who is nececery for Pat file(style),but that Midi file has only one measure betwen all markers.Then:haw to insert more measure betwen markers?
And anather question:
when I load Pat.file thru Style Compiler in Sonar I can see haw that style is maket.For all parts of style has markers who separate Major ,minor and seventh parts of style.My question is:what is the diferent betwen that Major or minor parts?Its the same and play the same and I cant hear diferent betwen Major or Minor parts.
Thank you