MIXED MEDIA : ** “DARK STAR--THE ROY ORBISON STORY” by Ellis Amburn <i> (Lyle Stuart Books, $18.95)</i> : <i> Items in this survey of pop-related videos, books and laser discs are rated on a scale of one star (poor) to five (a classic).</i>

The second Orbison biography to appear this year is long on good research--at least of the singer’s early days in Texas--and short on any understanding of the music’s power and impact. So, like a kinder, gentler, minor-league Albert Goldman, Amburn dully pokes into the darkness propelling the late rock pioneer. “Though he seemed a gentle, soft-spoken person, he was dangerous as a loose cannon . . . like his great peers Edith Piaf, Janis Joplin, Elvis Presley . . . driven by self-destructive forces that he never managed to control . . . rock ‘n’ roll’s most mysterious and tragic figure.” Oh, really? The poor fellow had problems and plenty of them, but these hardly seem to justify the tragic Greek-figure treatment suggested in Amburn’s fleeting non-expository passages.