Great catch Phaeton. I was getting nowhere with this - maybe because I was sure the error was in the header section. I am raising a bug report with Babylon to see if they can fix it.
You obviously know what you are doing so you might want to pursue an idea I never had time for. That was an animated 3d spectrogram that would change in step with the audio track.
ps - please post your own 3d spectrograms.
Not so sure about that … 
Sounds great, but I’m afraid I don’t have time either. 
I’d be happy to. Not sure if this is the right place though, since I ended up not using Audacity for the 2D spectrograms … 
This section of the forum may be more appropriate: General Audio Programming - Audacity Forum
Good news. Babylon have tweaked their code so that the 3D spectrograms are working again.
I had to alter the html file to suit so you should follow the tutorial example below if you want to try making your own.
This is cool. Imma try this.