the issue is that you are using the same form element for each download. This will trigger the first download to happen and prevent the second, you cannot do two download behaviors at the same time.
The work around is to create 2 separate submit buttons, One to download the ring tone, the second to download the song. Then in the Download file server behaivor, select the Buitton Pressed trigger for the coresponding button.
This will cause the ringtone download to happen when the ringtone button is pressed and the song download to happen when the song button is pressed.