When it comes to making ’em laugh, Tony Waag has little shame. Playing the ukulele is just the beginning. If he has to, he will get down on all fours and crawl after a laugh like a man thirsting in the desert. As a master of ceremonies, Mr. Waag has been known to launch into an impersonation of a chewing camel, methodically twisting the bottom and top halves of his mouth in opposing circles as he gums the air, then the microphone. Pity the act that has to use the microphone next.

This Tuesday at the Duke on 42nd Street, Mr. Waag’s New York City Tap Festival rattles into its sixth year. The festival promises yet again to demonstrate the diversity of contemporary tap dancing with themed programs that account for all the variables — age, race, national origin.And one of the programs even highlights comedy, something that’s a lot scarcer than it once was.

The program, called “Tap and Song,” is described as “a celebration of traditional vaudeville, comedy, and classic song and dance.” Mr. Waag is a competent song-and-dance man, but he’s most interesting as a representative of the neglected tradition of comedic character dancing. Of this tradition, Ray Bolger (the Scarecrow in “The Wizard of Oz”) is best remembered today, but he was just the tip of a vast iceberg of tapping funnymen. These days, though, there aren’t many of the breed left. Just as tap was once disregarded because its practitioners did too good a job of making impossible feats look easy, so the comedy tap tradition is neglected because its difficulty is masked.

It’s not that tap has lost its sense of humor entirely. Tap dancers still make jokes, good and bad.There’s also plenty of musical wit in the dancing — an allusion slipped in, a bit of phrasing so surprising that you have to laugh. All-out silliness, though, is out of fashion. “There’s a kind of playfulness that’s missing,” Mr. Waag said. “It’s gotten kind of serious.”

When tap was being revived in the 1970s and ’80s, it was seen as amateurish and nostalgia-driven; thus dancers tried hard to get people to take it seriously and recognize it as a richly expressive art. Tap moved into modern dance venues, and it acquired some of modern dance’s self-seriousness. The revered tap elders brought their old jokes and their funny steps into the new context and everyone laughed, but few in the younger generation — apart from comedienne Jane Goldberg — paid much attention to the connection between a hoofer’s timing and a comic’s.

“We picked up from the feet down,” said Josh Hilberman, another exception to the sober trend. “But the old guys were hilarious. “At the Duke, Mr.Hilberman will perform a one-man band number with taps, kazoo, and ukulele. (The ukulele community, he noted, is similarly anxious about that instrument’s comic roots.)

Racial sensitivities also come into play. (Ms. Goldberg and Messrs. Waag and Hilberman are all white.) Part of the legacy of minstrelsy was a perception of black dancers as comic almost by definition. That limitation and the general association of tap dancing with shucking and jiving had a lot to do with the dearth of young black tap dancers emerging in the 1960s, ’70, and ’80s, and it has a lot to do with an uneasiness with the word”entertainment”today.From a certain perspective, the old habit of telling a joke while dancing can look like making a joke of the dancing.

Something like that happened at the 2002 Tap Festival when Mr. Hilberman performed a dance called “The Warrior”with taps attached to his hands,his bare chest, his forehead, and to the front of the G-string that, beyond his tap shoes, constituted the whole of his costume. Mr. Hilberman worked up a beat that was at once rhythmically complex, satirical, and absurd. (The mark of taste was that he turned all the way around only once.) Yet halfway into the number, Savion Glover began voicing his disapproval from the audience. The act offended him, and when Mr. Waag called him up to dance at the end of the evening, he railed against it again.

After he taking a few vocal swings at the dance, Mr. Glover went into a dance of his own, a collection of his mentors’ signature steps. It was as if he were saying, “This is what real tap is.” As a demonstration of a heroic lineage,it was deeply moving, but it left a lot out.

“Tap is serious,” Mr. Hilberman said. “It’s also totally stupid. The danger is defining it in any one, reductionist way.”

Mr. Waag agrees. “The idea of comedy is subtle,” he said. “It’s not just telling a joke or making a face.” Each year, Mr. Waag allows his comedic character to slouch further toward comic rage, and tap can use that strangeness. The freedom to be funny needn’t be sacrificed in order to secure the freedom not to be.

The reductionist view would seem to have little room, for example, for the varied talents of Harold Cromer. At “Tap and Song,” Cromer will give the keynote address, singing “That’s Entertainment.” The octogenarian knows all about the great black comedy tap duos. He was Stumpy in “Stump and Stumpy,” and also did substitute stints with “Buck and Bubbles” and “Chuck and Chuckles.” He danced on Broadway and he held his own with the best of the straight-ahead tap dancers.

Mr. Cromer came up when all performers knew a little tap, and a tap dancer had to know a little of everything; cultivating comedic talent was a savvy career move, since comics were generally paid better. Every time he performs, it is as if he were saying, “This is tap dance, too. This is entertainment.” And he’s used to getting caught between shifting tastes. You can read about it in his upcoming book.It’s called “No Room at All.”

The New York City Tap Festival runs from July 8 until July 22 at the Duke at 42nd Street (229 W. 42nd Street, between Seventh and Eighth Avenues, 212-239-6200).