Doug.
Unless the pro you belong to is really broken, if you heard one of your songs being performed at a venue, you, yourself could have entered it on a live playlist submission to your pro, and not only would have you got your buck, but both the venue, and the performer would then be nown to the pro as playing songs under their umbrella.
That is how it works with my PRO and should with yours.
No good winging about what is wrong if you aren't prepared to do something toward getting things working.
If you aren't in a PRO, I suppose you could ask the performer to buy you a drink and tell the punters you wrote the song as an alternative, but I would suggest you plan your drinking for the night on it happening.
Graham

http://www.soundclick.com/bands/2/grahamhenderson_music.htm