Theremin Thursday : What would this meme sound like?



You may have seen this image, posted by Twitter user Threatening Music Notation. 

[Link to Youtube video in case you prefer viewing rather than reading.]

The first problem is that the notes are labelled incorrectly. Or mostly incorrectly. The second is that the notes aren't spaced correctly.

Or are they?  

Glossing over the labelling, could the designer have intended this to be a set of notes, spaced differently from the way that we usually do?

This idea intrigued me, and I set about finding a way to play the notes "as written"

We have to make some decisions here. It does look very much as if the spacing is four of their notes where we would usually write three, So I'm going to take that E (labelled D) G (correctly labelled) and B (labelled C) as anchor points, and fill in the frequencies from there.

I'm familiar with the table of values for the SID sound chip in the Commodore 64, this gives the values that we pass the SID to get particular frequencies. 

From that table we can take the values for E3, G3 and B3, and then fill in the rest, by division.


I know what you're thinking. "But Shiela, frequency values aren't linear (think the way the frets get smaller as they get higher on a guitar neck) and you've simply divided the space between E and G by 3".  You're right, and I'll come back to the linear thing a bit later, and I think these are near enough for now.

Anyway, this is a simple basic program to play those values, and you can see from my tuner that the E (second note) G and B (last note) are 'in tune'.

(result in video, embedded at the end.)

It doesn't sound as grating to the ear as I expected, I guess it might to someone with perfect pitch. 

There are a couple of problems with this. One is the linear thing. As mentioned, the 'in between' steps aren't supposed to be as equally spaced as I made them. If you know how to calculate these in a less linear fashion, please go ahead. 

The other, more problematic problem, is that E to G is 3 of our western semitones (let's not get into temperament here) and G to B is 4 semitones.  I get the strong feeling from the graphic that what is "intended" here is equal spacing all the way up. 


Only then did it occur to me that I'm in the middle of building a theremin-like instrument, and the thing about the theremin is that it allows you to play infinitely-variable frequencies. Not only that, but mine happens to have a perfectly linear scale.

I've already made this 'trainer' with the usual notes marked. So all I need to do is decide on some arbitrary 'anchor' points, I'm using the the E (labelled D) and B (labelled C) then divide that space equally. 

And this is how that sounds.



[UPDATE, later that day]

Thanks to Kevin at https://diyelectromusic.wordpress.com for helping with the maths, I've now updated my table of frequencies for the first attempt (which anchored the notes that are on the lines, e,g and b). The steps between those should be spot on now. 





Updated audio:

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