The notes are marked on each bar - that's why I blame the toy's quality rather than my tin ear. I do control the delays between notes, though, and that needs some work too.
If, by the first part of Through The Fire and the Flames, you mean the instrumental part at the beginning, I think the little Arduino would melt if it tried that. Besides, if I try to reduce delay between notes too much, it tends to just ignore some notes, as if it can't keep up. Part of that might be that I'm running all the servos through the USB port instead of with a good power supply. That seems to cause unexpected results, like the mallets getting into a sword fight with each other.
This is the first time that I've tried controlling more than two servos and I'm sure that there are things I don't know about making them all play well together.