You’ve just delivered your punch line, and wish to inform the audience it’s time to laugh. How many beats should your drummer knock out?

Most refer to the drummer’s punch line contribution as a “rimshot“, but opinion is divided on the number of beats a rimshot should contain. Some say 3, some say 4. Try verbalizing the sequence, and chances are you’ll say one of “ba dum bum,” “ba dum CHING,” or “ba dum bum CHING.” The first two have 3 beats, the last one has 4, so you know where you stand in the debate. But which one is right?

The practice of accenting a punch line comes from vaudeville theater, where the orchestra emphasized activity on the stage with short musical phrases (known as “stings”). Vaudeville had an 80-year Golden Era, in theaters all over the world, and it’s doubtful every orchestra punctuated jokes the same way. So 3 beats or 4? Both (and others) are probably technically right. But that hardly settles the debate…

When the facts don’t support one or other side of an argument, we traditionally look for a consensus of opinion instead. For that, we have The Internet:

Google
Google offers a list of pages that mention punchlines and phrases starting with ‘ba dum.’ While not statistically accurate, the first 100 results provide a representative sample: (NOTE: “CHHH” might also have been “pah”, “bing”, “ching”, or “tsss”… Something denoting a cymbal crash in any event, and it counts as a beat.)

On these pages at least, Google is unambiguous about the general consensus: whether it’s “ba dum bum” or “ba dum ching”, most people favour a 3-beat rimshot.

Internet Audio Samples
The Internet is thronged with audio sample sites, many of which contain “rimshot” clips. With duplicates the removed, there are 7 variations available:

The first five have 3 beats, and the others have 4 and 5 beats respectively. So again, the consensus is clear.

Anton Fig
Anton Fig is the drummer in The CBS Late Night Orchestra. He makes his living, in part, helping David Letterman’s audience identify Dave’s punchlines, so he may be the closest thing in the world to an expert on rimshots. Anton’s response to the original question:

The rimshot description Anton offered is the same as the audio sample “3 beat rimshot, variation 1” above, so the expert agrees with the consensus found on the other sources.

Put simply, then: your drummer should knock out a 3-beat rimshot to punctuate your joke.