Published Interviews

I have interviewed approximately fifty well known songwriters, which were published in several books and a number of magazines. All of the books are now out of print with the rights reverted to me. As far as the magazine pieces, most of them appeared in a magazine that granted me permission to use any of my old articles and interviews as long as I credit them. A publisher is interested in putting out a collection of my songwriter interviews in a new book. Do I need to get permissions all over again beyond the original ones? A number (eight) of these songwriters are now deceased. Do I need permission from the subjects to use magazine articles in a book? There will also be new interviews, for which I will definitely obtain permission.