The Music app being OOM killed really sucks. It'd be nice if at least it restored its state when you open it again, like Android music players do.
This sounds like a feature for music app, we should put this in music2, cc'ing Jim, Jacqueline and Sri.
This seems like something we could at least look into. Even some desktop players have this feature. That said, I hope we can make OOM less of an issue in the future so that this doesn't matter as much (probably by having more powerful devices).