There is a difference between publishing rights, which are typically owned by the artist for writing a song, the distribution of which without consent would be a civil infraction subjecting anyone using the song without consent to civil liability and copyright rights, usually once it has been fixed in a form that can be copied, such as being written down (sheet music) or recorded in a physical form. It is hard for me to envision how any taper making a recording without the consent of the artist would possess either publishing or copyright rights.
All that said, to me its really like how many angels can dance on the end of a pin. Unless the taper publicly distributed the tape or sold it, the artist (publishing rights) or the record label (copyright rights) really wouldn't care.