Her name was Joanne!

After Mike Nesmith left the Monkees in 1970, he formed the First National Band, and recorded an album... "Magnetic South".  He released a couple of singles from the album, but "Joanne" was the only one to chart.  A top 40 hit in the U.S. the song reached number 4 in Canada and #1 in a couple of other countries.  I like the song, it's kind of country, and very different... and a true forgotten oldie.