I rationalize file sharing (music) with the thought that anything that is played on the radio or TV may be freely recorded and shared with friends or strangers; just as if they had been tuned in themselves.
I would have no problem with paying money to the recording artists and their back-up musicians, even to the technical people and the editors. But the Labels and Associations are not on my Abused and Needful list.
Nobody loses money because I download anyway; I wouldn't be buying in any case. CDs that can hold 72 minutes of music are sold with 40, the same as vinyl albums, for about the same prices or higher, in spite of the lower production costs.
I do feel, though, that college and university computers shouldn't be used for heavy file swapping; the servers have to be up-sized to handle the extra load, and the costs have to be passed along.