Mixpoem started with James Laughlin’s curiosity about every possible arrangement of the words in Ezra Pound’s “In a Station of the Metro”:
The apparition of these faces in the crowd;
Petals on a wet, black bough.
By “every possible arrangement,” he clearly implied only the arrangements that make a sort of sense. That meant keeping the syntactic framework, such as it is, and shuffling the in- stances of the same part of speech. “Metro” consists of five nouns, three articles, three prepositions, two adjectives, and one demonstrative pronoun. Transposing the two adjectives is trivial, and reshuffling the prepositions or the articles is uninteresting. Obviously, what Laughlin had intuited was a noun shuffle. So the assignment came down to this: write the poem over and over with its five nouns permuted every possible way, thus generating lines such as the following:
The bough of these crowds in the apparition;
Faces on a wet, black petal.
Five words have 5 x 4 x 3 x 2 x 1 = 120 permutations. That meant 120 separate versions of the poem, and a lot of repetitive typing. Computers were invented to do repetitive chores. So I wrote a little program in BASIC that handled the “Metro” job (and nothing else). Then I got interested in a general-purpose mixer-upper. Hence “Mixpoem.”
It asks you to type in your initial text, marking the words you want permuted with slashes fore and aft, like this:
The /apparition/ of these /face/s in the /crowd/; /petal/s on a wet, black /bough/.
Since only what is between slashes gets permuted, whatever takes the place of “face” or “petal” will acquire the terminal .f outside the slash, and be automatically pluralized. Also we can arrange to have the first character of a line uppercased automatically, which is why I left the capital off “petal.” The twenty-four times “petal” is in that position it gets printed “Petal,” but “bough” when it moves there will likewise become “Bough,” and so on. (And if you are dealing with William Carlos Williams, you can turn the automatic capitalization off)