For this one it's "free for the first week" as an experiment to see how things go.
So far there's been a lot of great feedback and interest in just a few days (yours included -- thanks!). I don't think it would have been quite the same with even a tiny $0.99 price tag. Hopefully the decision to start as free makes sense in the long run. :)
I was expecting this to be around $4-9.99. Which I will gladly pay for a quality music app. You can definitely charge at least a dollar (which is basically free).