BK - The names of the songwriters are deliberately not on the ballot, and that they don't publicize the songwriters' names until after all the members have voted. (The audio of the songs are put on the MAC site, and they want the voters to listen to the songs and vote based on the songs themselves.)
That's why Sharon wouldn't know you wrote the song from her having voted for it.
This is from the MAC official rules for best song: (the page won't let me copy the link, but it's on the MAC site)
"Nominees in this category will be chosen by committee; the category will not appear on the preliminary ballot. The names of the writers of the submitted songs will not be revealed to the committee members during the judging process, and the names of the songwriters of the nominated songs will not appear on the final ballot. MAC will request the songwriters to similarly withhold from making such disclosure until the voting period has ended. This will allow all voting members to listen to the nominated songs on the MAC website and make their selections based solely upon the merits of each song. MAC will announce the names of all nominated songwriters shortly after the voting period ends."
