Hmmm. The only recording listed by Allmusic.com of THAT OLD IRISH WALTZ is by Robin Hopper her album "Pass It On," 2003. It's also listed at CD Baby, where you can hear a sound sample.

I'm guessing that's the same Robin who posted the above query in 2000.

I wonder if she ever found the songwriter?

I found a web page that says Lise Schnurr uses the pseudonym Lisa McCormick.

Anyway, here are the lyrics from the sound sample:

Well now, the country band plays that old Irish waltz.
Won't you dance with me tonight 'neath the stars,
And we'll dance 'cross the lawn and the moon will look out
When the country band plays that old irish waltz.

CHORUS: Shall we dance, dance like the trees in the wind,
Never to come to an end?
Shall we dance, dance for the rest of our lives,
For the old Irish waltz never dies.

What is this magical song? Why do I feel so free?
I'm floating and flying when you dance with me.
We are one, we are all, and the song is within,
When we dance on the hill to the old Irish waltz. CHORUS

[These lyrics might be incomplete.]