Accessing the song list does not require a permission (iOS6 and iOS7).
According to Apple (link for iOS6), Data Privacy section,
In addition to location data, the system now asks the user’s permission before allowing third-party apps to access certain user data, including: Contacts, Calendars, Reminders, Photo Library.
This policy has not changed for the newly-released iOS7:
iOS is designed to put your privacy first. For example, if an app wants your location information or data from Calendar, Contacts, Reminders, or Photos, it needs your permission first.