hmmm.....
I play in an originals band, we can get gigs when we want them and more often than not, the gigs we do these days are supporting signed bands. However, no matter how much musical integrity I have playing in my originals band, when you put me on stage in front of an audience of 4, opening for a signed band who have allegedly opened a gig in front of 25k people and send me home empty handed, then the following week put me in a packed pub full of people enjoying watching my covers band playing songs they all know, that I get a buzz off and then send me home with cash in my pocket, I know what I believe has more value.
I have to learn other people's parts, I don't read charts but I pick up tabs now and again to just make sure I am playing the thing right - sometimes it's easy, sometime's other people's parts are quite difficult to learn but I think it's made me a better musician by making me play in a different style to my own - ok so it's someone else's style, but so what?