It’s about time that Elvis Costello’s wife, pianist and singer Diana Krall, appeared on Spectacle (airing Wednesdays at 9pm EST/PST on the Sundance Channel)—after all, the cameras cut to her in the audience on most episodes, just another face in the crowd, a face that just so happens to be wed to the series’ host. So for this penultimate episode of the series, the spotlight’s hers. She appears alongside bassist Christian McBride and drummer Karriem Riggins, who back her up on a few terrific performances, including Nat King Cole’s “Exactly Like You” and the instrumental standard “Night Train”.

In order to provide some critical distance, the show’s executive producer, Elton John, appears as guest host—though very quickly he divulges that the two have been friends for nearly ten years, so I suppose “critical distance” may not be the apt term here. John has never interviewed anyone on television before, he points out at the start, and it’s obvious; still, he shares a pleasant rapport with Krall, makes a number of off-stage asides and witticisms to the crowd, and grooves out unabashedly during the performance pieces while leaning against the piano. The two talk piano and jazz and pop, covering Fats Waller, Bill Evans, Joni Mitchell, and Krall’s favorite, Cole. When they perform John’s “Sorry Seems to Be the Hardest Word” together, the results are less than stunning (“lounge-caliber indulgence” is the term that springs to mind), but not as bad as when the two tumble through an awkward, eerily lecherous “Making Whoopee” with Costello at the show’s end.