Do male singers have all the best songs?
No! Neither does The Devil have all the best tunes.

But, as has been stated above, many songs have been heard so often sung by men that the assumption is that they're 'mens songs'. An interesting point in case is "Danny Boy" which was written to be sung by a woman (the author even provides different words for when it's sung by a man Eily dear). The fact so many men sung it brought up the suggestions that it was being sung by a chieftain to his son, rather than just by a woman to her lover.

Cheers
Nigel