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That’s great. Have fun with that.

and if a person is dead, for example a singer, then can one appropriate his songs?

the author being dead only changes the fact that you cannot get permission from him/her directly. if you sing a song passing it as your own that is someoneelse's then that would be plagiarismregardless of the author being dead or alive, plagiarism is passing the work of others as your own.

copyright on a photo, my art is not considered a photo!

whatever the medium you make your art is irrelevant, it is still a derivative work. the copyright of the photograph covers all derivative works in any medium.

Photo copyright! Nobody gave a photo of his own!