Nice

I love the tin whistle (it was a tin whistle, right?), it sounds awesome.

The accordion sounded too smooth and clean, you can easily hear it's not real.

Also, it all sounded a tiny bit empty, I like when the music strikes you from all frequencies. But on the other hand, as it is it's probably better for flash ppl. It would work wonderfully as background music.

I couldn't help but notice that the melody of the accordion is very similar to that of Rhiannon by Faun. But it's probably a coincidence?

It all lacks that dirtiness I like in some neoceltic and pagan folk songs. And it actually sounds more like Irish folk than celtic music.

Anyway, I love it as a composition. Quite simple, but not repetitive. It's changing, it's progressing... Something's happening. Great job.