in my head the plumber reference is much more applicable to the touring end of the music business rather than the recording end. When a performer tours or a theatre company puts on a show, they have to be there to earn their money... if they put on a good show, they'll get repeat business etc (much like a plumber)
the recording end of the business i see more as an engineer or an inventor lol. its more about intellectual property, for the recording artist, the work is done once behind the scenes, and the product is produced... for an engineer, it's like have a great new idea, and getting a patent on it. the work is done once, but the royalties could come rolling in for years
luckily enough, i have no idea what i'm talking about, and just thinking out loud lol
for the record, i dont do downloads, i prefer to support the artist and purchase their albums (but i'm very old school
)