Cabin in the Trees/woods is the unofficial anthem of the Ranger corps. It was played at Will and Alyss's wedding in And About Time Too... and was also sung in some of the other books, once by Will and Berrigan, Will playing the mandola and Berrigan playing the gitarra.
Each yearly gathering the rangers end by singing their "anthem" and then they disperse to their own fiefs.
Going back to the cabin in the trees,
going back to the creek beneath the hill.
There's a girl who used to live there when I left,
but I doubt she'll be waiting for me still.
Never thought I'd be gone so many years.
When I left always planned that I'd return
but time slips away before we know
That's just one more lesson that we learn.
It is assumed that there are more lyrics to the song, but the above lyrics are the only ones revealed in the books thus far.
There is no official melody to Cabin in the Trees (as of yet), but there are fan interpretations to the song.
The song was written by Berrigan, a Ranger-turned-joungler