Anyone having trouble with the organ at Ultimecia's Castle?

[will_from_so_cal]

It seems like such a simple challenge: just hold down X, C, V and B at the same time and claim a Rosetta Stone as your prize! Only, no matter how many times I've tried it (and I must have tried it at least 20 times) there are still some spikes in the way. I'm hearing several notes on the organ at once, but it must not be all four notes. Please tell me someone else is having this problem!

[matheus.bt]

In case someone also lands here like me.
TIL that some keyboards have hardware simplifications that don't allow a group of keys to be pressed together in the same region. So depending on the map combination you chose, it won't be possible to "press it all together"
To solve this problem: temporarily map the keyboard to very spread keys (I used Q, D, V U)
Wasn't easy to get it done even with that (but I guess this falls into the game wanting a perfect sync on the key pressing) but it worked.