Decolonization gets the ultimate needle-drop treatment in the documentary “Soundtrack to a Coup d’Etat” from Belgian filmmaker Johan Grimonprez. It’s a dazzling, tune-filled collage of images, words and sounds, recounting the moment during the Cold War when Congolese independence, hot jazz and geopolitical tensions made a sound heard around the world. But also, how that music was muffled by lethal instruments of capitalism and control, still a factor on the global stage.

Built around the era’s influential players both famous (righteous Malcolm X, calculating Daj Hammarskjöld) and hidden (spies, hired mercenaries), the result is a riveting, deeply researched archival mixtape with the breadth of a period epic, the soul of an activist march and the pulse-racing energy of a cloak-and-dagger thriller. It’s a story told with beats, blues and voices, but also in onscreen text with citations, as if pages were being flipped. The effect, although lengthy at two-and-a-half hours, is dreamlike yet propulsive, a timeline that’s optimistic and sinister at the same moment. (An interview of blasé candor with pipe-puffing CIA chief Allen Dulles makes him come off like a Bond villain.)

The film’s organizing narrative swings back and forth from machinations at the U.N., where Khrushchev’s shoe-gavel taunts accompanied an emerging Afro-Asian bloc, to the violent chessboard that was newly independent Congo and the brief, espionage-ridden tenure of its first prime minister, Patrice Lumumba, the lightning rod of African independence. What “Soundtrack to a Coup d’Etat” makes clear through Grimonprez’s reckoning with his own country’s colonial wreckage is that Belgium — with the help of U.S. and British intelligence — had no intention of giving Lumumba a chance to gain a foothold.

Along the way we meet key figures like feared and maligned pan-African activist and advisor Andrée Blouin (her memoir excerpts are read by musician Zap Mama) and hear the poetic remembrances of Congolese author In Koli Jean Bofane (the clip-heavy doc’s only original interview), a child at the time his country was splitting apart.

We also get a broad, electrifying sampling of the era’s freedom jams, be they from our shore’s turntables and radios or the African rumba scene. Abbey Lincoln howls on Max Roach’s “Freedom Now” suite, Nina Simone’s urgent sound is heard throughout and significant morsels of Monk, Coltrane, Duke, Dizzy and Miles are all spotlit, often in meaningful juxtaposition with events and emotions in the narrative.

It was a time, after all, when jazz greats like Louis Armstrong and Melba Liston were dispatched as cultural ambassadors to Africa’s post-colonial regions, only to realize they were smokescreens for covert ops intended to undermine movements like Lumumba’s and protect multinational interests in the region’s valuable minerals like uranium. It was music as message, artists as distractions. But the 1961 murder of Lumumba, after months of plotting by U.S., Belgian and Congolese agents (and tacitly approved by President Eisenhower), signaled the end of the Western façade. It was the beginning of a fiery new human rights effort.

The very next month, Roach and Lincoln helped organize a protest at the U.N. Security Council. That angry convergence of jazz and politics is what bookends Grimonprez’s vault-driven, media-conscious inquiry, and sets the tone for the connective tissue of who’s who. In its audio-visual swirl of outrage, “Soundtrack to a Coup d’Etat” — one of the year’s very best documentaries — is nothing but deep cuts.