Sorry, I was playing hooky this weekend.
I used to get the same runaround from accounting departments – they truly do not know what the appropriate classification is.
I have gotten them as “salary”, however. I’ve also sometimes gotten them as “performance” and sometimes as “gao fei”. Depends on how good your relations with the recording studio or publisher or company are, I guess. Sorry I don’t have a more definitive answer. I do remember “performance” but that might have had to do with some video I was involved in one year.
The “gao fei” category of course allows a substantial deduction, which is nice, so ask for it if you can convince them.