Q, unfortunately the official song book through out history only provide a common base. As I've tried to track the sources of the 114 songs I was taught and copied into a personal songbook as a Counselor in training in 1973, I've discovered that putting oral tradition into the hands of 12-24 year old young women means that the popular songs of the day often become "traditional" in 20 or 30 years. (ie: Debbie Reynolds "Dreamer" from the movie Tammy)
I've found songs from the entire 50 year history of the camp that don't go back into the song book. There are still songs I've yet to find but that I can now musically trace to approximate time periods.