nanci griffith's signature song....
"I found your letter in my mailbox today
you were just checkin if i was o.k.
....
Just once in a very boue moon and i feel one coming on soon..."

other tunes i plan to sing at my gig tonight...
Bad Moon risin'
Coyote--the k.d. lang song that has howling in it!
NIght rider's lament where they read by the light of the moon and yodel
others??
for more info about blue moons see this link:
http://spaceweather.com/
and this one too:
http://science.nasa.gov/