If it is legal, then I see no reason why royalty free music sofware is a threat. Some artists put up their songs to be played in these types of settings just to get their name our there more and to have more exposure. I don't see it as a threat.
Royalty-free music software is not a threat. If people are going to listen to the artists music then the they are going to find a way to do it either by the radio or through the Internet. I think the artists make up their profits from album sales through touring.
Software that allows people to share music is no different from allowing people to listen to the radio. In the past, people could record music from the radio without having to pay royalties. In the same way, people should be able to record music that is available on the Internet.
No, royalty-free music software is not a threat, because musicians and the people who produce it still have many ways to earn a profit. Musicians might have to earn their profits by touring, which they used to do. Music software only makes music more accessible, but it does not change that people need to purchase the music.
I do not believe royalty-free music software is a threat. There have always been free music options, its just something no one really wants to use, because it doesn't offer what is popular. Free and good are rarely synonymous, and the same goes for royalty-free music software. There's always a better option and it generally costs money.