I don't believe the number 13 is unlucky, but since some people do I thought I would post "Taps" as my 13th song. Virtually everyone is familiar with it, even if he or she never attended summer camp:
At Camp Ajawah, the bugler would play this every night at 10 pm to signal lights out, no more talking, everyone should go to sleep. Hearing it echo across Lake Linwood and through the pines was a lovely way to end the day.
At Girls' Camp, it was also part of the medley of songs that ended each evening's campfire, where we all held hands and sung. One camper famously misconstrued the following lyrics:
Day is done, gone the sun,
From the hills, from the lake,
From the sky.
All is well, safely rest,
God is nigh.
She thought the song began "Dave is done..." because that was (and is) the Camp Director's first name. It works.