SquareZ
It's the heart afraid of breaking that never learns to dance
--Amanda McBroom (The Rose)
Calling Ideas for March 28, 2012

This is:

Respect Your Cat Day
In 1384, King Richard 11 of England issued a royal edict condemning the eating of cats.

I don't have any cat-related singing calls. I suppose there's Memory (from the musical Cats), and Rock this Town (by the group Stray Cats), but those are major reaches.
Three Mile Island Meltdown
Here's a description of the event: Inside Three Mile Island

How about Neutron Dance?
Reba McEntire's Birthday
Here's Reba's official site.

Songs that I recognize as having singing call versions:


There are probably a lot more that I don't recognize, not to mention all the covers she did.
Number 1 Songs
These songs (that I recognize as having singing call versions) were number 1 on this day:

1945: Accentuate the Positive
1990: Black Velvet

March is:

Optimism Month
Encourage and inspire each other to be optimistic about the future of square dancing.

Here are some songs that come to mind: