This method is causing the data to be updated, but the name implies it is just an accessor, returning the play count.

This also will fail in any race condition, where your cached value for the play count will be added to not the value in the db.

Instead, use an update statement like this:
http://apidock.com/rails/ActiveRecord/Base/increment_counter/class
```
AudioFile.increment_counter(:play_count, self.id)
```
that replaces lines 73-75