I'd like to see if MathML works, so I will describe here how to calculate the frequencies of the notes on the piano.
First of all, we start with middle A. Its frequency is 440 Hz. We get to the next octave by doubling the frequency, the next highest A is 880 Hz. But if we look at the keys of the piano, there are 12 notes between one A and the next. So, we split the intervening range geometrically like this:
Ahhhh, apparently MathML doesn't work in Drupal. Hmmm. That is pretty sucky...
How about JSMath? Grrrr, that means using Tex. Well, got to have something. Ok, this function describes the displacement of, say, a speaker tweeter while playing note n on a keyboard, where note 0 is middle A, note 1 is middle Bflat, note 2 is middle B, etc. $A_{max}$ represents the maximum loudness of the signal. We can also think of this function as returning the numerical values which go into an electronic audio file (e.g. a .wav file) which can then be "played" by some computer software.
If we want to skip the black notes on the keyboard, we can start from any point, say middle C ($n=3$) and progress from there as follows:
$n_i=3,5,7,8,10,12,14,...n_{i-7}+12,...$
to make some kind of scale of C major.
Hmmm, at least you can see something sensible. Annoying though, as I would like to be able to paste in MathML. Many programs produce it as output... This really is a temporary measure.
So MathML is produced by many useful things like Open Office and Mathematica, wheras Tex always has to be inputted by hand. And JSMath is not an ideal solution, since in order to display properly in a browser, you need Java installed, plus a series of fonts. Also, it takes several seconds to decide what it is going to display in your browser. Compare this to viewing a page of MathML in firefox. It is instantaneous. You need to install some fonts too, but it does a good job of displaying basic mathematical expressions without them.
I want MathML to work in Drupal. Grrrrrr.
The only alternative apparently is to change the header of your theme's template file to an xml header. The problem with that being you have to write everything as correct xml in all your pages. That's not so bad, but also, everyone who writes comments on your pages has to do the same. One single tag out of place, and the whole page goes down. Hmph.