Music on multiple pins

This is probably going way off the beaten track here and maybe the answer is "it probably cannot be done".

I would like to play music on multiple pins but if I try:

``` python
music.play('a:30', microbit.pin0)
music.play('b:30', microbit.pin1)
```

it plays the second note on both pins. If I use `music.pitch` instead of `music.play` (which is what I really want because I'm being even more contrary) the note turns into a distorted screech.