> There is nothing different about the plumber and the artist. > Both would like to be paid for their work.

No. A plumber wants to be paid for work, your musician wants to be paid a rent. A plumber wants to be paid once, your musician wants to be paid for every copy.

If your musician comes to me and offers to make a song, and I agree to pay to fund it, then fine: we make an exchange just like a plumber and customer. But a plumber does not then impose restrictions that I cannot copy their pipes and stuff, or cannot allow anyone else to use them.

A plumber is not given special monopoly privileges -- that is the difference. Now, such privileges might be pragmatically justifiable as a market mechanism (as is the contention of copyright), but there is clearly a difference between having them and not.