Spectacle: Elvis Costello With...

Interspersed with cover songs, Spectacle is an engaging showcase for a curious mind.

The best moments in Wednesday night's chat between Elvis Costello and Elton John, which are good enough to recommend the show for fans of both men, serve up small but sparkling musical pleasures.

Insightful, smart and lyrical, Spectacle soars when so much of cable TV seems intent on locating the most distressing nadir of human culture.

Costello (who has subbed for David Letterman) makes a fine host--a bit reverential at times, but never as pious as, say, James Lipton can become over at the similarly configured "Inside the Actors Studio."

All the performances are rough and under-rehearsed, which makes them appealing. Costello also keeps the atmosphere relaxed during the interviews, never seeming too eager to interject his own commentary or jokes.

While the unguarded moments and eclectic musical performances --typically Costello collaborating with a guest on one of his or her lesser-known hits--make Spectacle well worth a closer look, the show occasionally feels like a songwriter's version of "Inside the Actor's Studio," with all of the qualities and the faults that implies.

Alas, the program has little direction and almost no flow.