Who killed the composer?

The Composer Is Dead.

Actually, he's alive, Nathaniel Stookey is, and clearly relishing the dozens of recent performances of his new work, The Composer Is Dead.

The creator of the text, Lemony Snicket, is narrating the aforementioned music.

He's not dead, and his real name is not Lemony Snicket. He's Daniel Handler, the tremendously popular author of A Series of Unfortunate Events books, who is doing the piece for Saturday's Philadelphia Orchestra family concert.

Still, the composer is dead, and the question eats at you like a Lachrymose Leech: Who killed him?

All in good time, which is exactly what the Stookey-Handler collaboration promises to the 2,500 children and parents skilled enough to acquire a ticket to Saturday's good-as-sold-out concert.

It promises, too, an orchestra of suspects and a full musical investigation. By the end of the half-hour, listeners will know where the violas sit, what French horns sound like with stop mutes crammed up the bell, and which instrument gets picked on anytime a composer wants music sounding like a bird.

Think of it as a fey Peter and the Wolf, a cross between the Young Person's Guide to the Orchestra and Clue.

"It's a murder mystery for narrator and orchestra, and it introduces children to the orchestra - whether or not they want to be introduced," said Handler after a performance of the work last month in Verizon Hall for a group of schoolchildren who, in fact, looked remarkably rapt.

Handler and Stookey knew each other in high school, lost touch, and after reconnecting decided to write a piece together. Why did the duo, who both live in San Francisco, decide on this theme?

"If you think about it," said Stookey, "every composer you can think of is dead."

But to hear Handler tell it, the reason to write something was that existing pieces dead composers wrote for children were not very good. One need not mention names, but Handler does, and he says he set out to write something better.

We don't know about better. But it is louder. Handler's outsize stage personality accounts for much of the work's captivating power. It's hard to imagine anyone but him delivering gags with the same mood swings - from understated and dry to over-the-top, shouting delirium.

An excerpt:

(Mysterious, creepy music)

Composer is a word which here means a person who sits in a room muttering and humming and figuring out what notes the orchestra is going to play. This is called . . . composing.

(Same creepy music)

But last night, the composer was not muttering, he was not humming, he was not moving or even breathing. This is called . . . decomposing.

The crime established, the narrator sets out to find the murderer.

Stookey's music - which will be recorded by the San Francisco Symphony to accompany a book version of the piece to be released in January - is skilled and memorable. He's an admitted lover of Peter and the Wolf, and a shade of Prokofiev shows up in the first few bars of the work.

One of the funniest and most strangely satisfying sections is a duet for a milquetoast tuba and his landlady, the harp. You don't hear that combination every day. The roles Stookey gives to instruments, though, are generally idiomatic - a flamboyant solo for the concertmaster, for instance, and march-happy but sometimes violence-prone writing for the brass instruments.

Before the murderer is revealed, Stookey cycles through a deft weave of quotes from his dead colleagues - the "Marcia funebre" from Beethoven's Symphony No. 3, Bach's St. Matthew's Passion, Brahms' A German Requiem, Mozart's Requiem, Schubert's Death and the Maiden, Haydn, Mahler, Chopin, Tchaikovsky, Stravinsky, Schoenberg . . . a Who's Who of Death in Music.

The list is offered as proof that the murderer has, it turns out, been stalking composers for years.

"It was by far the hardest part of the piece," said Stookey, who dovetailed the quotes in their original keys, referencing them for just enough notes to be recognizable.

The Composer Is Dead also indulges in the arcane repertoire of musician humor and the curious way in which players often share characteristics with their instruments - poking fun at the self-pitying violas, the egomaniacal concertmaster, the shifty oboe player, rude brass players.

"As Daniel says, it's a piece that tricks people into listening," says Stookey, using a phrase that here means you'll probably learn something about the orchestra without even realizing it.