Jazz trumpeter Ambrose Akinmusire. (Autumn De Wilde/ )

There are times when even the unlikeliest of jazz ensembles are so attuned to each other, so profoundly inspired and inspiring, that a writer’s clever prologue can do nothing but demean the work. Tuesday night’s Kennedy Center concert by trumpeter Ambrose Akinmusire and vocalist Cécile McLorin Salvant, fronting a combined jazz band (Akinmusire’s) and string quartet (New York’s Osso Quartet) was one of those times.

The nine musicians assembled in the Terrace Theater performed Akinmusire’s original, Kennedy Center-commissioned suite. Neither the suite nor its component parts had any announced titles. They didn’t need them. The consistent, haunting melancholy of the music and lyrics — most of them spoken word, with Salvant’s vocals mostly wordless — were communication enough.

It was also a case study in how intensity doesn’t necessitate either volume or speed. The closest the evening came to either was in a somewhat wild piano improvisation by Sam Harris, accompanied by the jittery bass and drums of Harish Raghavan and Justin Brown, in the fourth piece. At times it approached the chaos of a free improv, although the harmonies held fast. Even here, though, the rhythm section kept the same softness of gait that characterized their work throughout — a softness that the other musicians echoed.

Indeed, while he was working against Osso, whose parts echoed a Beethoven quartet, it was Akinmusire who evoked Beethoven’s famous direction “beklemmt”: as though being physically crushed. Already a stirring, penetrating player (his style calls to mind a quote from Louis Armstrong: “Those pretty notes went right through me”), Akinmusire adopted a strangulated tone on one solo, deflating notes even as he blew them, and played growls that shook the sound loose from his horn like a hunting dog with its quarry. This is an example of how the music beggars description: The above sounds unappealing, but in fact it was deeply affecting.

Equally affecting, however, was the vocalist. Salvant, arguably the most acclaimed jazz vocalist of the 2010s, has been known to over-enunciate, to over-emote, in a way that undermines her credibility. This obviously wasn’t an issue in her wordless vocals on Tuesday, or in her spoken word. But when she finally sang lyrics on the program’s fifth tune (with the refrain “I am strengthening toward you”), her restraint was marvelous. Salvant would come to the precipice of oversinging, offer the suggestion that she might go over the edge . . . and miraculously pull back at just the right moment.

It was a remarkable bit of artistry, in synch with everything else on the Terrace Theater stage. And, along with everything else, its effect was profoundly moving.