By Hook or by Crook

What’s the difference between a hook and a ditty? Available definitions don’t offer much help, I’ve discovered. The following definitions are available from answers.com:

Hook (n.):
1. a. A curved or sharply bent device, usually of metal, used to catch, drag, suspend, or fasten something else.
b. A fishhook.
2. Something shaped like a hook, especially:
a. A curved or barbed plant or animal part.
b. A short angled or curved line on a letter.
c. A sickle.
3. a. A sharp bend or curve, as in a river.
b. A point or spit of land with a sharply curved end.
4. A means of catching or ensnaring; a trap.
5. Slang. a. A means of attracting interest or attention; an enticement: a sales hook.
b. Music. A catchy motif or refrain: “sugary hard rock melodies [and] ear candy hooks” (Boston Globe).

Ditty (n., pl. –ties):
A simple song.
[Middle English dite, a literary composition, from Old French dite, from Latin dictātum, thing dictated, from neuter past participle of dictāre, to dictate.]

So apparently the word “ditty” refers to a complete song, while “hook” refers to a rhythmic figure or melodic line, that is, a specific element of a song. So is a ditty (song) necessarily composed of more than one hook, or just one? To me, anyway, the origin of the word “ditty” from the Latin dictātum (“thing dictated”) suggests that a ditty is easy to remember (“simple”). Information theory would then tell us that a ditty has a low probability of being transmitted incorrectly (“distorted”), another way of saying it is easily remembered: how many times did you have to hear “Happy Birthday” before you remembered the whole song? Once? The popular TV game show Name That Tune is premised precisely on this insight, that one needs only a few notes in order to have total recall of a song. (I best remember the version of the show in the Seventies hosted by Tom Kennedy, but historically there have been several incarnations of Name That Tune, beginning in the 1950s.)

Are the best pop songs, then, no more than ditties? According to Gary Burns, in “A typology of ‘hooks’ in popular records” [Popular Music 6:1 (Jan., 1987) p. 1], the word hook

connotes being caught or trapped, as when a fish is hooked, and also addiction, as when one is hooked on a drug. These connotations, together with the idea of repetition, are captured in the Songwriter’s Market definition of hook: ‘A memorable “catch” phrase or melody line which is repeated in a song’ (Kuroff 1982, p. 397. Bennett (1983) defines hook as an ‘attention grabber’ (pp. 30, 41).

Music critic Lester Bangs was never comfortable with the multiple connotations of hook as “catchy,” meaning hook as that which catches or ensnares the prey, is addictive, and is seductive and appealing as candy. He wrote:

Listen, I hate hooks. The first time I saw the word “hook” was in a review of a Shocking Blue album in Rolling Stone in 1969. The author had evidently discovered that songwriters sometimes used it and now informed us that the bass riff was the almighty “hook” in their hit “Venus,” that one irresistible little melodic or rhythmic twist that’ll keep you just coming back and back and back and buy and buy and buy. (“Every Song a Hooker,” in Mainlines, Blood Feasts, and Bad Taste: A Lester Bangs Reader, Anchor Books, 2003, pp. 351-52)

Freud argued that repetition is pleasurable because we associate it with the pleasure of the mother’s breast (or bottle) from which we nursed (sucked, in the sense of reiterated action) as infants. Whether one believes this argument is irrelevant, because in fact the most successful pop songs (measured in terms of economic success) prove the point anyway, with their relentless repetition--reiteration--of melodic lines and rhythmic figures, a practice justified in order to make a song "suitable for dancing".

Lester Bangs cited “Leader of the Pack” by the Shangri-Las as a positive example of a song with hooks, while Kim Carnes’ “Bette Davis Eyes” is a negative example (an instance of music business "cynicism"). I might cite “My Guy” by Mary Wells as a positive example, or The Temptations' "Just My Imagination (Running Away With Me)," the type of song that if I hear it early in the day I hear it the rest of the day (in a good way). But if Bachman-Turner Overdrive’s “Takin’ Care of Business” comes on the radio, the radio goes off--as fast as my synapses can fire.

For further reading:
Lick
Riff
Theme
Melody
Ostinato