OAKLAND, Calif.-- Dear Ozzy Osbourne,

The following is said with the utmost respect. You are a true pioneer, a living legend, and you deserve some slack--and have been granted plenty in recent years.

But it's time to get off the stage. Not the larger public stage, as you remain one of music's endlessly entertaining personalities. It's the concert stage for which you are no longer suited.

In a show at the Oakland Arena recently, you were a shell of your former self in every conceivable way. Your voice failed you on several occasions, you were at least a step slow throughout the night, and you were forced to resort to shooting fake snow out of a fire hose to keep the attention of even the diehards in front of the stage.

And what's with all the jumping jacks? It's perfectly acceptable at your age to use your performances as your regular cardio workouts, but do you need to make it so obvious? You might as well have been wearing leg warmers and a headband.

You were admittedly under the weather, so I don't want to be too harsh. But I wish you'd cut your set by 15 to 20 minutes instead of letting Zakk Wylde's guitar solo go on interminably while you recharged backstage.

Wylde was solid throughout the night, but his furious riffs and speedy solos exposed your most glaring weakness: You just can't keep up the pace. You shined on your ballads like "Mama, I'm Coming Home" and "Mr. Crowley," but stumbled repeatedly to stay with Wylde and company on speedier fare.

It's not entirely fair to compare you to Rob Zombie, who opened the night with a blistering, dark, and fascinating set. But the juxtaposition of a multidimensional menace and one that is simply nostalgic and contrived was impossible to ignore.

Zombie put on a fantastic show, using clips from his various films and music videos to sync with the songs, and generally keeping the crowd amped. "Dragula" was superb, mixing in clips of Herman Munster drag racing in the car for which the song was named.

Speaking of video, the most entertaining part of your set was the video montage at the beginning, with you being inserted into various movies and TV shows, including Pirates of the Caribbean, The Queen, Lost, Entourage, Borat, the OK Go treadmill video, Sopranos, The Office, among others. Seeing Ozzy Osbourne inserted into a Dancing With the Stars segment in which you pull off Heather Mills' prosthetic leg is pure comedy.

But if we wanted Ozzy Osbourne as comic, buffoon, and drunk uncle, we could just as easily rent The Osbournes on DVD. As a live performer, your sun has set, and unlike loads of other geriatric rockers who still tour, you haven't managed to mine the relics of your youth with dignity.