It's not news that Stephen Sondheim's body of work doesn't contain a lot of love songs. Even when he does a show with a love story -- even love stories that end happily, as they do in A Little Night Music -- you won't usually find a number where the lovers express their love in song. Instead he'll provide torch songs for the moment when love seems lost ("Send in the Clowns," "Losing My Mind") or songs about how love sucks ("Every Day a Little Death"). Even Passion has hardly anything that can be called a love song, though this may be because it has hardly anything that can be called a song.
This leads to a lot of speculation about why Sondheim doesn't write love songs. There are two standard explanations for this, the esthetic and the psychological. The esthetic explanation is that Sondheim is the guy who moved beyond all the banalities and lies of the traditional Broadway musical, and that includes the lies of the traditional Broadway love song. In other words, Sondheim won't have a character sing "There's a small hotel" because then that character would be lying: there isn't a small hotel! Nor a wishing well. It was all destroyed along with the American dream sometime around the Korean war.
The other explanation is that there's something in Sondheim's psyche that makes him unable to write a straightforward love song. Sammy Cahn, a specialist in superficial but successful pop lyrics, once said that Sondheim was "afraid to say I love you" in song, and others have offered the same explanation using more redundant words.
I'd like to offer an alternative explanation: the reason Sondheim doesn't write love songs is that he's not very good at writing them.
(Note: what I write below is mostly about Sondheim as a lyricist. His music has its problems too when it comes to love songs -- most notably that his constant repeating of musical phrases tends to make love sound indistinguishable from obsession.)
Sondheim's strengths are well-known; he's great at writing for character, putting complicated concepts into song ("Finishing the Hat" is not nearly as good as Cole Porter's "Never, Never Be an Artist," but it undoubtedly has more to say), and creating genuine musical theatre that moves the show along rather than stopping it. Give Sondheim a specific theatrical situation, like, say, two people singing about making corpses into meat pies, and he'll come through. But give Sondheim a spot for a love song, and he collapses into generalities and cliches. "Johanna" in Sweeney Todd is a collection of banal ballad-isms:
I was half convinced I'd waken,
Satisfied enough to dream you.
Happily I was mistaken,
"Not a Day Goes By" from Merrily We Roll Along, in both its versions (it appears in the show as both a straightforward love song and an anguished "don't leave me" love song), is a love song without a single distinctive image in it, a generalized Ballad 101:
Not a day goes by,
Not a single day,
But you're somewhere a part of my life
And it looks like you'll stay.
This tendency to generalization and cliche reaches its apogee (apex? something that starts with ap) in Passion, where a ballad called "Loving You" starts with a line that could have come out of an I'm-OK-you're-OK pamphlet:
Loving you is not a choice,
It's who I am.
Sondheim's problem with love songs is that they require the exact opposite of the kind of talent he has. Sondheim's talent is for specificity: taking a very specific character or situation and building a song around it. (When preparing to write "I'm Still Here" in Follies, he made notes about who this woman was, what her background was, what she'd done, who she'd known -- and put it all into the song.) A love song requires that the songwriter build a song around the most generalized situation imaginable: one person in love with another person or vice versa. Sondheim specializes in finding ways to say what no song has said before; the key to writing a good love song is finding a unique way to say what has been said a million times before.
The great writers of lyrics for love songs tend to be the ones with an offbeat, whimsical sensibility, the ones who approach familiar things from unusual angles. These include two lyricists whose work Sondheim has criticized: Lorenz Hart and Ira Gershwin. Both had a tendency to cuteness and self-conscious playfulness; both had trouble writing in character voices other than their own; both could be sloppy (though Hart's technical sloppiness, which Sondheim often complains about, didn't really become a problem until late in his life, after his drinking got worse). But both of them could turn these things to their advantage when it came time to write a love song, because they were the kind of lyricists who would ask themselves: what's a new, offbeat way to say "I love you?"
You can see this most easily in the titles of their love songs: not boilerplate like "Loving You" but specific-sounding titles that don't seem to have much to do with love. Taking Hart as an example, the titles of his love songs include "Have You Met Miss Jones," "I've Got Five Dollars," "Like Ordinary People," "Every Sunday afternoon," "I'll Tell the Man in the Street." One favorite trick of the great writers of love songs was the "concealed" love song, where you don't know it's about love until near the end. The Gershwins' "They All Laughed" starts as a list of famous people whose innovations were laughed at; then in the B section we find out what the song is really about: "They laughed at me wanting you." Rodgers and Hart's "I'm Afraid" is a list song about all the things the singer is afraid of, but reveals its true colours at the very end of the refrain:
I'm afraid of Fu Manchu,
And of tigers in the zoo,
But most of all
I'm afraid I'll fall
For a horrible thing like you.
Another trick in writing a love song is to load the song with unusual images or metaphors, to disguise the usual-ness of the subject matter. Hart, again, does the metaphor bit a lot, as in "Love Never Went to College" from "Too Many Girls":
Love never went to college,
Ignorant boy, that,
But think of the joy that he starts.
His work requires no knowledge,
So he can do it
By using intuitive arts.
He just says "You two kids,
Start falling in love.
I ain't got brains
But I reigns over all these parts."
Love never went to college,
Never had teaching,
And yet he keeps reaching our hearts.
Sondheim can't do this kind of thing very well (all right, I guess he'd jump at the chance to write that "A horrible thing like you" line) because writing a good love song depends on a willingness to approach things from an unusual angle, and Sondheim doesn't do angles; he tackles things head-on: what is the situation, who is the character, what will express this situation and character in song. That's not to say that he's unsubtle (as someone once said on a newsgroup, Sondheim has a character sing "Here's to the ladies who lunch," not "I'm a bitter old cynic"), just that he focuses on specific things, specific situations. His images are of things that are physically there (George is finishing a painting of a hat, so he sings "Finishing the hat"), his metaphors are those that people might plausibly use in conversation ("The road you didn't take"). All this works fine when you have a unique character and situation to work with. But with a love song, you have nothing specific, or almost nothing; you're left with the necessity to find a way to say what has been said before. In that kind of situation, a talent like Sondheim's -- rational, measured, kind of literal -- is at sea, while an off-the-wall talent like Hart or Gershwin or Harburg or even Bob Merrill will be right at home.