It's a surprisingly old usage. Here's one from 1786 saying a sum of money is to the tune of two millions and a half. Coincidentally, I'm just watching the 1962 remake of Mutiny On The Bounty, where Captain Bligh says it matters to the tune of £1000 a day that breadfruit should arrive in Jamaica as soon as possible. It's set in 1787, so Hollywood got the speech of the times right there.
TheFreeDictionary: tune definition 2 has...
- a. Concord or agreement; harmony: in tune with the times.
- b. Archaic Frame of mind; disposition.
I think both those two senses, paricularly the latter, would have made it barely even metaphorical to use "to the tune of" for "about like that" or "of that ilk". Maybe someone can track down a "first recorded use", but I doubt that would represent the coining of the expression.
I suspect shifts in the meaning of "tune" have led to the current situation where OP is not alone in thinking the expression seems a little odd. So now it's thought of as an idiom, we continue to use it for money but don't feel comfortable transferring the meaning to other contexts.
LATER: Here's a usage from 1738 writing of a publication containing 9764 "Questions & Answers" (an early precursor to EL&U!), in which the author mentions an earlier publication with "to the tune of Nine Hundred [Answers]". The referent isn't/wasn't always a sum of money.
Matt's idea that the phrase might have a different meaning in each saying seems probable to me.
I've been slightly more successful searching for see a pudding crawl on its own (without the laughing part). And it is a lot more frequent with creep than crawl.
There's a peak in the early 19th century for see a pudding creep because it was used in an essay by Jonathan Swift :
it would vex a dog to see a pudding creep
where it could be understood as "see a pudding go to waste".
The oldest quote I have found is in a 1617 nonsense anonymous verse :
I grant that Rainbowes being lull'd asleep,
Snort like a woodknife in a Lady's eyes;
Which makes her grieve to see a pudding creep,
For Creeping puddings only please the wise.
Here again it's the idea of waste. So how did it become associated with laughter? (A hint of sadism maybe?)
The phrase seems to be British (rather than US), here's an excerpt to what seems to me to be a pastiche from the TV series Star Treck:
"You would laugh to see a pudding crawl..." Spock read aloud, an eyebrow almost rocketing off his face. "...a fascinating image."
Kirk gave him a weird look. "I never thought I'd say this, but that's one of the only phrases I haven't heard Bones say."
"That is hardly surprising, Jim, as it originates in Britain."
It can found in a cockney dictionary and a 2005 excerpt from a web blog:
But then, us Londoners, as my dad used to say, would laugh to see a pudding crawl.
Best Answer
We're applying a French word to a Russian practice. This can only go wrong!
More seriously, we're not even doing that, but the dining practice at most high-end Western restaurants that don't highlight the following of a particular ethnic practice is a late-20th Century adaptation of service à la russe.
Now, the fact that the English term for this is to use a French term that means "service as the Russians do it", is a potted history of this approach all in itself. Indeed, generalise that to "the English term is a French term that means how they do it outside of Western Europe" and you have a story that has repeated itself several times in the history of haute cuisine.
Service à la russe means that you have several courses, which are brought to the table as the previous one is finished, or ideally after just the right length of pause (a skill that sets a Michelin star quality meal apart from a merely excellent one, in itself). But really it means more than that, and what we have is the result of over a hundred years of changes to that style of dining, that is changing still as innovations from the far ends of the spectrum from the likes of Noma and the Fat Duck on one end, and fast-food establishments on the other, work their way into the middle. For a start, we most often eat only 2-3 courses with maybe a couple more on special occasions and even a 3-hour tasting menu may have less than a dozen courses (I don't recall one going above 12 including amuse-bouche and petit fours) where originally service à la russe would have frequently had 13, 14 or more courses.
Before then, we had service à la française which was also sometimes called service à l'anglaise, but which wasn't really called anything until the French and English wanted a name to mean "the way we used to do it, before this new fancy Russian way became fashionable". This is close to a buffet style, but with some items brought to and from the table (what the Scandinavians still call "cold table" is close, if generally less showy).
Most of the food would be laid out on the table in a manner designed to impress on first sight, with a roast ready to carve part-way through the meal, but some would be brought to the diners, and taken from them when they were finished.
These dishes would be brought in with some fanfare, of which the best modern example (indeed, one that often goes beyond how it would have been in those days) being the piping of the haggis such as I would have enjoyed on Friday had their been any justice in the world and I hadn't been too busy to celebrate Burns Nicht properly. That is to say, they would have made an entrance, or in French, une entrée.
Even at this time, just which dish (or perhaps, just which entrance) counted as the entrée wasn't a point of universal agreement, which possibly owes more to hosts' desire to place the focus on a dish other than the first, that they were particularly proud of leading to the term being applied to a course after the soup and/or fish, than to either of those.
So, in using entrée at all, we're using a term of imprecise meaning, for something at some point in a particular type of service, while practising an adaptation of yet another type of service, in which we have much fewer courses, and in which those courses are nowhere near as well defined in terms of contents or sequence.
Really not all that surprising that we don't agree on what it actually means, is it?
I suspect that confusion over just what does and doesn't count as an entremet didn't help matters either (strictly a small dish between more substantial dishes, but it's an even older word being applied to an even more recent course, so it can be even less well-defined).