My first reaction to news that "Buffy the Vampire Slayer" was planning to air a musical episode was, "Wasn't that fad killed off, like, three years ago when 'Suddenly Susan' did a musical episode?"

Then I thought: Maybe "Buffy" waited this long because they wanted to make it a really, really good musical episode.

Yep, that was it. Even with the crummy audio quality of the preview tape sent to me by UPN, it was obvious almost immediately that this will be an instant classic as soon as it airs Tuesday, November 6th.

Remember when Sunnydale fell under a spell that rendered its citizens mute? Well, now something's put a song in their hearts and a spring in their step. It's the musical curse, fresh evidence that Broadway songs are from the devil - and maybe tap-dancing, too. With its frequent non sequiturs and ambitious lyrics, the show strikes a pitch- perfect balance between whimsy and earnestness.

A show's story line is usually suspended in these musical episodes, but there's a significant development in the closing frame of this "Buffy." Be warned, however: The version I got went 50 minutes. A standard episode is 44 minutes. Set your VCRs accordingly.