Giving bands "free advertising" does not absolve copyright. If that were the case, then torrents, for example, would never be illegal because an infringer could always argue they are giving away the music or movie to promote it.
Essentially, if you do not have permission from the copyright holder, then you are infringing on copyright. It's really as simple as that. If you are doing this to help out the bands, why don't you just ask the bands for permission and avoid this issue altogether?
Giving bands "free advertising" does not absolve copyright. If that were the case, then torrents, for example, would never be illegal because an infringer could always argue they are giving away the music or movie to promote it.
Essentially, if you do not have permission from the copyright holder, then you are infringing on copyright. It's really as simple as that. If you are doing this to help out the bands, why don't you just ask the bands for permission and avoid this issue altogether?