Thank you for all the comments. Clearly the phrase is used differently by different people.

The reason I ask is that I'm embarking on a dissertation based on information acquisition and adaptation, with folk song as my topic. I think it's admirable that singers of folk songs are often so diligent about crediting their sources, and generally seem interested in a song's provenance. I've been studying the liner notes from a lot of LPs and CDs and the phrase 'from the singing of...' crops up a lot. I was hoping there was some consensus about its application, but obviously there isn't. I needed to clarify that, so thanks again.