Why is it that a pharmaceutical company spends billions upon billions on R&D and only gets to patent it product for 20 years, but some poxy artist/record label

Why is it that a pharmaceutical company spends billions upon billions on R&D and only gets to patent it product for 20 years, but some poxy artist/record label gets paid royalty for a cajillion years. There's something very wrong there... I'm in 2 minds about the whole medicine patent thing. One the one hand, as you say, new medicines would not be developed but on the other hand the patents drive the prices so high that people in 3rd world countries cannot afford them. It also means medicines for 3rd world diseases are not worthwhile for the large pharmas. There really needs to be a better balance, maybe spending 5-10% of their R&D on medicines they know will never see it's return on investment but will save many more lives than their high profit products.