Norm Macdonald is pretty fearless on talk shows. No matter what show he’s on — I’ve also seen him convulse Conan O’Brien pretty often, too — Macdonald establishes his own rhythm. He’ll risk frittering away his couch-time chasing a rhythm just out of reach, or he’ll catch the rhythm and really rides it out, until a producer signals the finish-line.

This night, Macdonald was, as Letterman sometimes says, solid gold. He talked about a pork chop, the difference between eating at home and in restaurants, and told stories about people we are unlikely to hear about on talk shows once Letterman retires: Giants of men like sportscaster Bob Uecker, comedian George Miller, and actor Jack Warden.

Miller, who died in 2003, was a special favorite of Letterman and Macdonald’s, a hard-working club comedian, a pal of Letterman’s since the host’s own stand-up days. Macdonald and Letterman shared favorite Miller jokes, and trust me, Norm gets Miller’s tone and pacing down impeccably here.

Part of Macdonald’s recent history is his activity on Twitter, where he has conducted a (serious?) campaign to replace Craig Ferguson, told a tale about meeting Bob Dylan (since deleted — the tweets, not Dylan), and got a lot of traction doling out tweets chronicling behind-the-scenes writing sessions for Eddie Murphy’s appearance on the SNL 40 special. Macdonald has been ill-served by television, as the uneven 1999-2001 sitcom Norm proved, but he got good stories out of his TV experiences, and Wednesday night told one such tale about actor Jack Warden.

Even better was Macdonald’s anecdote about Bob Uecker. This was Macdonald at his finest, commencing the bit with some thoughts about Las Vegas, cast in Macdonald’s unique phrasing, a mixture of the conversational-vulgar and the fussily precise (no one else would say “gossipy small-town whores”). You can see Letterman relax during this segment, the way he does when turning over the proceedings to a guest who’s in full command of a story, especially if it seems to be a meandering one that’s nevertheless headed for a good punchline.

Letterman and Macdonald acknowledged that this would be the latter’s final appearance with Dave. (“I understand there’s only 12 shows left” — trademark Macdonald: the confident error). As Macdonald gathered himself to go, Dave said, “Could be the funniest man in the world. God bless you.”

The band played to commercial as Letterman and Macdonald rose and Dave gave Norm the most sincere hug I’ve seen the host give a guest in a long time. It was, all in all, another one of those talk-show segments (two, if you want to get technical) that are never going to exist again once Letterman exits the scene.

The Late Show With David Letterman airs weeknights at 11:35 p.m. on CBS.