FaeDyne, those numbers don't correspond to the keyboard, Frolic numbered them arbitrarily so (s?)he could tell us the song without resorting to using pictures of each note.
***Contains significant spoilers regarding boss fighting strategy***I beat Golem and am now at the first save point in the body! I found that mouse motion and firing isn't accurate enough for boss battles (I get my fingers all tangled

), so I use WASD for motion and focus on shooting and dashing with the mouse; but mouse motion / firing is more comfortable for general gameplay (left hand hovers over form shortcuts). I was able to beat Golem on my second try after I figured out the pattern, relying heavily on defense foods (stock up! You should only need one at a time until the effect expires. Do they even stack?).
A good strategy is to stay low, since you can dash under his jumps and over his runs. When I was high up I couldn't see him coming until it was too late and his jump was too high to avoid. When he gets super pissed near death, stay high and go from side to side while scarfing defense foods. My dodging (and presumably most other peoples') wasn't good enough to dodge both him and the machine gun jellies. Up high you only need to dodge jellies (not too hard) and accept the occasional painful jump (insignificant with defense food). Another useful tidbit: you can go right through the lady, running into her doesn't damage you*. Thus avoiding her isn't necessary and is one less distraction during a tough fight. You should definately have all you health+ eggs by now. One last piece of advice, when he jumps at you I think the amount of damage you receive is based on how long you're in direct contact with him (not sure though).
Now that I'm no longer frustrated, I can appreciate how clever that puzzle was. the position of the notes etched in the wall give away the actual second song:
X Y Z A
_ _ _ B
_ _ _ C
The blank sections on the wall correspond to a repeat of the three notes on the first line, with the final (fourth) note being changed. Had I figured this out PRIOR to getting the song from this forum, I wouldn't have had to rely on my (crummy) ears. I have rarely before
underestimated the cleverness of a puzzle in a video game. It floors me that two people made a game this beautiful when teams of dozens or more put out substandard garbage on a regular basis.
*Not confirmed in the second half of the battle, when she shoots at you. Probably a better idea to stay far away anyways, since you can't dodge her shots from up close. Can you eat them when they're fired at you?
Thanks everyone, now I'm taking a break to enjoy some other gifts

You've all been very helpful