Traditionally payment & accounting has never been a problem in the music business, so I think blockchain would not really help. The underlying economics is what has changed dramatically. Distribution is close to free, but unlike the ~ $1 an artist might have seen out of a CD sale (before discounting for costs & advances) they now see sub-cents on a single track. You used to pay $15-20 for an entire album to get 2 or 3 good songs; now you only stream everybody's top tracks and pay less than that a month. So the artist gets a couple of pennies for the period when they are hot, then nothing.