I sing what I like as a general rule. If I have a request made by a client far enough in advance, I will learn that song for that gig. I may never sing it again.
I've sung the same Types of song for most of my performing life but the repertoire changes from time to time. Sometimes I just get tired of a song and stop doing it, other times I learn a version I like better and make the change there.
I have written a few songs that have been well received and I perform them but not to the exclusion of all else. I'll sing other peoples songs if I like them and if the original owners don't mind. I'm eclectic in my tastes; everything from Childe Ballades to Shel Silverstein and I'm working on a couple of Tom Waits numbers.

troll