Whenever we speak, we make music.
Well, okay, that's not entirely true. But in voiced (not whispered) spoken English, every speech sound has a pitch. In most utterances, the pitches stay fairly constant from one syllable to another, though pitch rises at the end of a question and falls at the end of a statement; but some common phrases have well-known tunes to them. I had a few teeth out a few weeks ago, and couldn't talk for a while; I was fascinated by how much I could communicate through intonation. "Mmm" can mean a lot of different things depending on pitch and stress.
Peter Berryman (who wrote the lyrics to the all-purpose state anthem "Your State's Name Here," among dozens of other songs) brought all this to my attention in his February 1998 "Whither Zither" column. He pointed out that the near-universal (at least in America) tune for calling someone to dinner uses a descending minor third: start with one pitch, then go down three half-steps to the second pitch. In solfège notation, this descending minor third can be denoted "so-mi"; the phrase "John-ny, din-ner!" is sung as so-mi, so-mi. (So in the key of C, the notes would be G, E, G, E.)
Turns out there are other phrases sung/spoken to the same tune, and lots of other phrases that incorporate that same minor third. As you come in the door, for instance, you might sing out "Honey, I'm ho-ome!" (so-mi, do so-mi). Your honey might reply "Door's op-en" (so, mi-mi). If ta's made dinner for you (lucky you!), ta might sing "Come and get it!" (mi mi so mi). And if you're on your way, you might sing "Com-ing!" (and we're back to so-mi again).
There's a familiar taunting tune that goes "so-so-mi-la-so, mi"—you can sing anything from "Suzie's got a boy-friend!" to the generic taunt "Neener neener neeee-ner!" to the old standby "Ring around the rosy" to that tune.
And there are recorded songs that use some of these intonation "tunes" as well. Peter Berryman added in a later "Whither Zither" column that Harold Arlen, the composer of "Somewhere Over the Rainbow," got the interval for "Someday I'll wish upon a star" (so-mi so-mi so-mi so-mi) from calling his dog. And my favorite part of John McCutcheon's lovely song "Calling All the Children Home" is the beginning, which he says his mother sang to call him and his siblings in to dinner: "John-ny, Mary-Claire, Lu-lu, Jean-nie, Kev-in, Jeff, Patty, Nan-cy-y, Rob." Each of the first five names is so-mi (or soso-mi, as necessary), and the rest of the names (starting with Jeff) resolve it nicely (so, mi-mi, re, mi-re, do, I think).
Berryman also points to a great site with lots more about intonation, the Pentatonic Music Collection. Follow the "spoken intonation" link for many tunes to phrases. Not all of them work for me, but some are spot-on, such as the resigned comment "Give him his mon-ey" (so so so mi-mi). I'll leave it as an exercise for readers to determine tunes to phrases like "Good mor-ning Mis-ter Hof-fa!" (a class greeting a teacher), and the annoyed phrase "Hel-lo-oh!" (as one might say when cut off in traffic).
I'm fascinated by spoken-word recordings in which intonation almost provides a melody. There's a Scott Johnson recording which includes clips of someone saying, "Remember that guy, J-John somebody? He was a— he was sort of a jerk" over and over. It's not really a melody, but when repeated it begins almost to sound like one. Peter Berryman suggests elaborating on this notion by recording conversations and basing melodies on them. Jim Moskowitz adds that minimalist composer Steve Reich has used spoken-word techniques like this, most famously in a piece called "Different Trains," which uses recordings of people talking about 1940s US passenger trains and Nazi concentration-camp trains.
Every now and then I find myself about to start singing a poem, and realize that I can't sing it because it has no real melody. That impulse seems to have something to do with intonation (though perhaps more to do with rhythm). Peter Berryman notes that "poems are a subgroup of songs, defined by having no set melody." He goes on to note that it's odd that many modern poets read their work aloud in a droning arrhythmic monotone—what a poet friend of mine calls "poetry voice." I much prefer poetry that's written so that when it's read naturally, the rhythm is obvious; a songwriter friend of mine takes this further, composing melodies partly based on the natural pitches of ta's lyrics.
If you have access to a Macintosh with speech-synthesis software installed (as it is by default in most recent versions of MacOS), you can experiment with changing the intonation of the computer voice. Create (or open) a text file in an application like SimpleText that can speak text aloud; enter some text and play it back using the speech software. The computer voice modulates slightly, changing pitch at the ends of questions and sentences, but doesn't sound very natural. If you want it to sing to you instead of attempting natural speech, put this at the start of your file:
[[pmod 0.0]] [[pbas 60]]
The first part tells the software not to modulate words—to stay on a constant pitch until told otherwise—and the second part indicates what pitch to start with (in this case, 60 half-steps up from the lowest available pitch). You can then insert absolute pitches (such as [[pbas 72]]) or relative pitches (such as [[pbas +12]]) into your text. Have fun!