DYLANOMICS: It’s no secret that Bob Dylan...

DYLANOMICS: It’s no secret that Bob Dylan has written a sheaf of songs over the years that he never got around to recording--or releasing. Now ever-resourceful Rhino Records has put together a compilation of versions of songs Dylan hadn’t put out (at least until his recent “Bootleg Tapes” release), aptly titled, “I Shall Be Unreleased.” Due out in late August, it features a host of gems and oddities, including Rod Stewart’s “Only a Hobo,” Johnny Cash’s “Wanted Man,” Doug Sahm’s “Wallflower,” Dion’s “Farewell,” the Staple Singers’ “John Brown” and Paul Revere & the Raiders’ “(If I Had to Do It All Over Again, I’d Do It) All Over You.” . . . The success story of the week is Natalie Cole’s “Unforgettable,” her musical tribute to her father, Nat King Cole--and her debut for Elektra Records. In only its third week on the charts, it has rocketed into the Top 10, a major achievement (even in the new Billboard era of instant No. 1 albums) considering that Cole’s last Top 10 album was 14 years ago. The real winner here--Elektra chief Bob Krasnow, who spirited Cole away from EMI Records and gave her free rein to do the tribute album. Cole had wanted to do the project at EMI, but her old label didn’t want it. . . . And the lo-o-o-ong wait is nearly over. It’s been three years since Metallica’s last album, but the speed-metal kings return in mid-August with “Metallica,” produced (for the first time) with an outsider at the helm, veteran hard-rock studio-hand Bob Rock. The 12-song collection includes such new material as “Enter Sandman,” “Sad but True,” “The God That Failed” and “My Friend of Misery.”