Nobody really knows what killed Mozart, but he died while he was writing his Requiem. He'd been feverish for weeks, and he even declared that the Requiem would be his own—and then it was. Did he die from the sadness of his own music? He was buried in a common grave, according to Viennese custom, on December 7, 1791. The day of the funeral was "calm and mild," according to the big book of music, the Grove Dictionary. The Requiem was unfinished.

Scientists use pieces of Mozart's Requiem to evoke sad moods when they want to test the psychology of sorrow—seriously. That's how sad it is. But the Requiem is more than 40 minutes long. Which part is the saddest? The most heart-wrenching? The part that STOPPED MOZART'S OWN HEART? In search of Mozart's killer, I asked musicians playing the Requiem with Seattle Symphony this spring which part of it—which actual notes—they found the saddest. Then I locked myself in a soundproof room for hours listening to their suggestions over and over, trying not to weep.

Benjamin Butterfield, tenor

Proposed saddest part: The first eight bars plus Lux aeterna soprano solo

"In the opening of the Requiem, it's the sadness and simplicity of the writing, the sparse instrumentation, and the sad little non-vibrato clarinets that soar over it all," Butterfield says, "only to then be obliterated by the full orchestra with the brass and choir inciting 'Requiem.' The way that line is then made even simpler in the last movement by just cutting straight to the soprano solo (who is talking about everlasting light shining on the dead—the Lux aeterna) is more than I can take sometimes."

In the lab: Soft moans escaped test subject at the early moment of clarinet obliteration. Formation of lonely tears ensued. Later soprano solo did not reactivate tear formation but did invoke faint memory of it, causing heaviness in the chest.

Sadness level (1–10): recommendedrecommendedrecommendedrecommended

Clayton Brainerd, bass-baritone

Proposed saddest part: Last five measures of the Rex tremendae

"There are a few measures in the Requiem that simply transcend all earthly realms," says Brainerd. "This musical idea comes from out of the blue and only lasts a very few measures: the last five measures of the Rex tremendae. It is as if the heavens softly open and angels appear to sing these few measures and then as seamlessly evaporate into the ether, leaving us completely humbled, blessed, and changed! It kills me every time!"

In the lab: Subject barely kept it together in the first three agonized cries ("Rex! Rex! Rex!"). By final five measures, tightly furrowed eyebrows gave way to light sobbing.

Sadness level: recommendedrecommendedrecommended½

Jill Becker, musician and symphony spokeswoman
Proposed saddest part: The Recordare

"The harmonic interplay between each solo voice as it enters always puts a lump in my throat," Becker says. "Mozart achieves this by using suspensions, a relatively simple harmonic tension/release device that never fails to provoke an emotional reaction for me! The Recordare is also a movement where the soloists' voices are extremely exposed—it feels to me to be the most human and vulnerable section. (Now, if you're looking for the most heart-pounding section, it's the opening Confutatis, hands down! Love the fire and brimstone of the low voices and the orchestra.)"

In the lab: Subject experienced very little sorrow for the first few measures. Harmonic resolution repeatedly stalled oncoming blubbering. However, the stabbingly panicked line "ne perenni cremer igne" (and rescue me from eternal fire) brought on a brief howl of mourning.

Sadness level: recommendedrecommendedrecommended

Me, Jen Graves, person writing this

Proposed saddest part: The Lacrimosa

Hate to disagree with everyone else—but what about the Lacrimosa? When Mozart died, only the first eight bars of the Lacrimosa were written: Surely these are the ones that immediately preceded, even precipitated, his death from heartbreak. The steady, rhythmic, funereal rise of the chorus through segments of harmonic tension and resolution to a staggering plateau are overtly sorrowful, but saddest of all because they are also so terribly beautiful and so terribly final.

In the lab: Bawling began early and continued throughout. Through tears, subject then begged to hear Lacrimosa again. This brought on louder, desperate wailing.

Sadness level: recommendedrecommendedrecommendedrecommendedrecommendedrecommendedrecommendedrecommended