The wonderful jazz standard Mack the Knife began life as a song from the the musical play The Threepenny Opera - which is not actually an opera despite its title. It's actually an early example of what we know now as musical theatre, which developed around the end of the 19th century out of the light comic operettas such as those of Gilbert and Sullivan and their contemporaries.
2018-01-07 Rerun commentary: To reveal all, it does. (spoiler warning) And it will hint at an event in the past that will have readers debating about whether it's a true revelation or merely a one-off gag with no further significance. It will be quite tricky coming up with dialogue that reads almost sensibly backwards, but then makes perfect sense only when you realise what's happening in the first panel and read it forwards. In foresight, this will be one of my favourite strips that I will have written.
You know what?
I was just looking at this comic and wondering what the heck I could write for an annotation... and it only just occurred to me that this comic makes a reference to Hell, and it's numbered 1666, a thousand plus 666, the traditional number of the beast.
So no, that wasn't deliberately planned. I don't generally do things to tie the comic in with the comic number. I have, on occasion, but I try not to make a habit of it.
2018-01-06 Rerun commentary: 666 is quite an interesting number, mathematically speaking. It's the sum of the first 36 natural numbers (1 + 2 + 3 + 4 + ... + 36 = 666), making it the 36th triangular number. It's also the sum of the squares of the 5th and 6th triangular numbers, 15 and 21 (152 + 212 = 666), and 15 and 21 themselves sum to give 36. 666 is also the sum of the squares of the first seven prime numbers: 22 + 32 + 52 + 72 + 112 + 132 + 172 = 666. This isn't particularly astonishing though, since pretty much every number has some wacky mathematical properties that look amazing, until you realise that all numbers have similar things.