Cool!!!!! Thanks!
Interesting.
How many of these interval signals can you recognize?
http://www.youtube.com/watch?v=hFRYKDF2kxs
Once upon a time, this one mattered. Maybe it will again. The jury is out.
https://www.youtube.com/watch?v=wPGOmWnaaMI
At some point, they changed over to Yankee Doodle. Here it is, as it sounded over the air: