On Alpha Ralpha Boulevard

In Cordwainer Smith’s story with this title is found the following songlet:
She wasn’t the woman I went to seek
I met her by the merest chance
She did not speak the French of France
But the surded French of Martinique.

I cannot find this poetry elsewhere. Did Cordwainer Smith compose it for the story, or did he know it from some earlier source? Is there more of the song? And what exactly does “surded” mean in this context, and how does it come to mean it?