[GraemeJ]

I half expected MSP to play the mp3 when I touched that symbol, but it's just that I guess.

I think it would be neat if the audioplayer would start the mp3 from a press of the symbol (like an action button) if this conforms to your design and code, Mike.

The little note symbol merely indicates there is one or more audio files associated with that chart.

I'm not sure your idea has much merit.  MSP is designed as a sheet music reader, not an MP3 payer.  I can think of few reasons why you would want to play the audio without seeing the chart and even then, if you just wanted to listen to something, is it so bad the chart is displayed at the same time?  

It is possible to set up MSP so that the associated music file is automatically played when you open the chart.  I would have thought that was enough, without adding yet more code.

Following the KISS principle, I'm not sure I really understand your reasoning behind your other idea concerning the display of all the meta data?