I have been called many things in my life: morally promiscuous, a soldier of fortune, and a mercenary.

While not exactly true, these labels are not false, either. For years I worked in Africa, preventing wars from starting, ending them after they began, and picking up the shards once they abated. But I am not a diplomat, a soldier, a United Nations official, or a humanitarian worker: I am a “contractor,” as we say in the business. Governments and big corporations hire me to do covert military work they can’t be seen doing themselves; I’m a public-sector soldier gone private.

Working in the private military industry involves exotic travel, tropical diseases, interesting people, and risk. I’ve raised small armies in Africa, conducted arms deals in Eastern Europe, supported unpopular corrupt regimes, and prevented genocides before they could occur. I work with the unsavory characters that the UN doesn’t want to be linked to, and if something should happen to me—such as being captured by an insane warlord and his seriously disturbed child soldiers—I’m on my own.

When you hire me, one of the “value adds” for big clients like national governments is plausible deniability: Unlike public-facing efforts, they are able to claim ignorance when an operation goes horribly wrong. And where I work, “horribly wrong” is the norm, not the exception.

My job is an adrenaline rush, but something else makes my heart beat: opera.

Opera and war

For a man in my profession, there’s much to love. Like war, things usually go horribly wrong in opera.

For instance, take Verdi’s La Forza del Destino or “The Force of Destiny,” a title that sums up the vibe of Italian opera of the 19th century. It involves love, family, a curse, guns, revenge, war, God, and twisted fate. (And let us not forget mercenaries like myself.)

Like war, things usually go horribly wrong in opera.

La Forza is a tough opera—which is my kind of opus. In 1960, a baritone at the Met dropped dead on stage after singing the aria “Morir, tremenda cosa” (“To die, a terrible thing“). He fell face-forward, an opera KIA. After that, Pavarotti refused to perform La Forza, thinking it cursed. Likewise, noted tenor Franco Corelli conducted small rituals before going onstage to ward off fate’s cruel hand.

The story begins like this. Two sworn enemies—enemies only through cruel twists of fate—chase each other all over Spain and Italy, yet do not actually know what the other looks like. (Very opera.) As a result, they coincidently join the same band of mercenaries, save each other’s lives, and become fast friends, thus invoking the Sacred War Buddies Bond. (In Africa, I found night battles invoke the same thing—just quicker.)

But even sacred bonds can be broken in opera, which plays for keeps. Soon—again through strange fate—they learn the other’s identity, and the chase resumes. Don Alvaro decides he’s had enough with fate and checks into the local monastery to live out the rest of his days in nonviolent celibacy. However, clever Don Carlo tracks him down after five years on the road and shows up to deliver justice, Olde World style.

Opera’s best swordfight scene ensues. Carlo shows up at the monastery disguised as a pious wanderer and asks for the priest’s absolution, knowing full well it will be his sworn enemy Alvaro. Carlo then challenges him to a duel, throwing a sword at the unarmed monk’s feet with the orchestra sounding combative music. It’s the kind of composition that makes you want to reach for your rapier and skewer a living creature, adding exclamation points to Carlo’s taunts.

Alvaro looks at the weapon heavily, and turns away. He says (although the tenor of the music explains it all on its own) that he has left his former life behind and is a transformed soul, pursuing God’s grace.

Defiantly, Carlo rejects this as hypocritical drivel and hurls insults at him. Verdi magically weaves Carlo’s vendetta with Alvaro’s redemption into a duet that brings one sitting on the edge of their velvet seat. Finally, the demands of honor trump those of devotion, and Alvaro picks up the weapon and cries, “Ah! death, come forth to death! Let us go!” Steel clashes to the fury of music, and you know there will only be one man coming out of the room alive. Just like African politics.

At this point, you may be scratching your head with your opera binoculars: What does a gent like me who has spent decades doing dirty work with maniacal scoundrels love so much about acrobatic yelps and filigreed theaters? Admittedly, there are few in my line of work who would embark on a pilgrimage to the Bayreuth Opera House or cry during “Casta diva.” But I am not alone.

Meet Tobias Hume.

The original opera-obsessed mercenary

Living from around 1569 to 1645, Captain Hume was a bit before my time. He was a Scotsman, composer, viol player (think of a seven-stringed cello), professional soldier, and mercenary. He fought for the Tsar, swore like a pagan, and died of old age, penniless.

To live among war is to walk in the shadow of humanity’s worst nature.

Hume’s most famous client was the Swedish King Gustavus Adolphus during the Thirty Years War, a boom time for private soldiers. Back then, Sweden was not the innocuous nation of Ikea and social welfare: It was the scourge of Europe. Its armies swept through central Europe like a pike through Jell-O. Resistors were defenestrated or had horse manure shoved down their throats. German children still sing horrid songs of the Swedish occupation.

When Captain Hume was not a halberd for hire, he composed songs. Only two collections survive: The First Part of Ayres (or Musicall Humors, 1605) and Captain Humes Poeticall Musicke (1607). Despite Hume’s day job, his music is soft, soothing, and subtle. It stars mostly the viola da gamba (another long-lost instrument that is like a cello) and often includes voice. This is not music to attack by, but rather reflect on the day’s glory over the evening campfire.

How can a mercenary—a profession that demands inhumane judgement—feel so passionately about music? As Hume prefaced in The First Part of Ayres:

“I Doe not studie Eloquence, or profess Musicke, although I doe love Sence, and affect Harmony: my Profession being, as my Education hath beene, Armes, the onely effeminate part of me, hath beene Musicke; which in mee hath beene alwayes Generous, because never Mercenarie. To prayse Musicke, were to say, the Sunne is bright.”

His tone is gruff, raw, and direct. His music, however, is not. Hume’s hit parade includes: “A New Cut” (ouch!), the suggestive “Cease leaden slumber: The Queenes New-yeares gift” (ooh la la), and the timeless mercenary mantra,”Good Againe.” There are military overtones throughout his work: “A Souldiers Resolution” starts with strident bowing, evoking reveille in boot camp. It is followed by what sounds like soldiers running around garrison, changing of guards, cleaning weapons, marching in formation, stacking munitions, digging ditches, peeling potatoes, and other timeless soldier activities. All expressed via viol.

Little is known of Hume’s life, save a few letters and the portrait that his music paints. Toward the end of his days, when he writes that his “Fortune is out of tune,” he begged Queen Anne, to whom his second collection is dedicated, for charity. However, none was received, and he died poor and nearly insane at the Charterhouse Hospital.

General Douglas MacArthur famously said that “Old soldiers never die; they just fade away.” Old mercenaries don’t fade away so much as whither.

Soothing the savage beast

Music is important in war. It marshals the military through its endless marches, gives instruction through the bugle, and induces the inner Berserker in us all. But those who know war, like Hume, do not glorify it with such superficialities. We know music’s true and secret power in war: It rescues the soul.

To live among war is to walk in the shadow of humanity’s worst nature. In West Africa, I saw emancipated amputees crawling the streets begging for a few cents. During the blood-diamond war started by Liberian warlord-turned-president, Charles Taylor, militia would enter a village and offer people “long sleeve” or “short sleeve”: If you opted for long sleeve, they would hack your hand off; if you said short sleeve, they would chop your arm off below the shoulder. Sometimes, for fun, they would take two, three, or even four limbs. Most victims would bleed out on the jungle floor. The (un)lucky ones were saved and now scrape across the filthy streets of Monrovia.

Steel clashes to the fury of music, and you know there will only be one man coming out of the room alive. Just like African politics.

It’s the same in central Africa. Eastern Congo is a sponge of badness, where the worst of the worst gather owing to its lawlessness. UN troops rarely exit their bases for fear of slaughter by the warlord du jour. Militias make sport of villagers, brutally raping the women while forcing the men to watch. Children are made to shoot their parents as initiation into the strongman’s child soldier ranks. Those who refuse are shot by another 12 year old. Women are kidnapped while fetching firewood and turned into sex slaves by local military commanders.

Opera is my lodestone in the darkness. Its beauty offsets war’s ugliness, and without such balance, we slip into numbness and eventual insanity, robbed of our humanity. Perhaps this is why the more horrors I witness, the deeper I cling to my opera.

A few years ago I was working in the Great Lakes region in central Africa. It was here that the Hutu-Tutsi genocide ripped through Rwanda, Burundi, and the eastern Congo in 1994. 800,000 people slaughtered in 90 days. That’s almost two souls per minute. And some of those paid for the bullet rather than being hacked to death with a rusty, dull machete.

Since then the area has known only war and ash. Extremist groups are still trying to re-ignite the genocide and complete their grim unfinished business. One of these groups, hiding in the wild west of the Congo, wanted to assassinate the president of Burundi. They knew that if successful, the government would implode, followed by the country, followed by the region. They wanted to recreate Valhalla burning at the end of Wagner’s Götterdämmerung, African style.

My job was to keep the president alive, in public view, and not guarded by a bunch of white guys carrying machine guns wearing sunglasses—and I had to do so with a limited budget, total invisibility, and it had to be done yesterday.

I kept him alive—but that’s another story.

In the first days of my visit, I wandered into the depravity of the jungle. There, I found one of the various unmarked killing fields, just outside Bujumbura, Burundi’s capital. It was an area where an untold many had perished. I had visited such ghastly sites before, from the outskirts of Phnom Penh to the beach dunes of Liberia. But Buj was different, owing to the vast scale of the atrocities.

As I walked the ground, the tread of my boots scraped up old bits of clothing and children’s teeth, emerging from the earth a decade later. I stood enraged. I was livid. I wanted retribution—like Don Carlo. I felt the darkness.

Then an opera aria wafted through my ears. It was like cool water on hot pavement: “Vesti La Giubba,” from the opera Pagliacci by Leoncavallo. It’s an aria of egregious pathos, scorned humiliation, and despair. Sung by a clown who discovers his wife’s infidelity, the aria grieves his lost love and steels himself for what lies ahead.

Turn your distress and tears into jokes,

your pain and sobbing into a grimace, Ah!

Laugh, clown,

at your broken love!

The lyrics swirled in my head and subsumed my soul. Just as the clown had to turn his anguish into jokes, I too had to find purpose in tragedy.

Pagliacci showed me the way. I bent over and scooped up the small molars, staring at them in my palm before closing my shaking fist.

“Not again,” I thought. “Not on my watch.”

Sean McFate’s latest book, The New Rules of Law, is out Jan. 22.