The gloves were off when The Crossing choir arrived at the Philadelphia Fringe Festival on Sunday.

This new-music choir is often ready to take on complex social issues, though this concert went beyond protest with the fierceness of a street fight. Titled Of Arms and the Man, the program of works by Ted Hearne, Gabriel Jackson, David Lang, Louis Andriessen, Sebastian Currier, and others confronted immigration, corporate greed, and climate change head on (and will be repeated at The Crossing's three sold-out performances at New York's Park Avenue Armory on Sept. 19 and 20).

President Trump was never named, but his infamous quote in May about some deported undocumented immigrants — "These aren't people, these are animals" — was the basis of Ted Hearne's Animals, a musical sucker punch that was premiered on Sunday. The usually mellifluous Crossing singers delivered a meticulously controlled cacophony of animal noises with the Trump words initially embedded in the texture and then hammered away over and over in syncopated monotone, as if this could become the new normal. Then Hearne delivered the consequence of that normal: A vocal transcription of one of the displaced immigrant children in a detention center calling out for her parents. Devastating.

Whether or not this and much of the music heard with it on Sunday survives the crises they document, the point is that serious composers are strongly engaging with their world rather than rising above it. Must they aspire to be timeless? Not when agile institutions like The Crossing and the Fringe Festival can respond to the outside world even more quickly than some of their pop-music counterparts.

Much of the concert was assembled by Crossing artistic director Donald Nally from past programs but sequenced with an ear for rhetoric more than music. Yes, the sung notes were important. And yes, the excerpt from Kile Smith's Where Flames the Word felt as sublimely beautiful as ever. But overall, commentary was paramount, even in David Lang's depart, which is sung wordlessly but with ample implications.

Gabriel Jackson's 2013 Rigwreck went on to specifically name British Petroleum in its pointillistic ricochet description of the 2010 Deepwater Horizon oil disaster with unvarnished rage that doesn't make for great art but was more effective than ever. It led up to Lang's 2015 Last Spring, which gently enumerates what the composer loves about the earth — from melting snow to grass turning green — with music conveying a profoundly sad farewell.

The FringeArts headquarters had a decisive influence on the piece's presentation. The dry acoustics favor words over the choir's fine tone quality. The seating area leads right up to the edge of the stage, which meant that performers and listeners were all in it together. Further intimacy was achieved when the concert began with singers and three cellists sitting in a circle on the floor with lighting that suggested stories around a camp fire.

The drawback was that the concert's strong conceptual banner made you focus on the message at the expense of the creative process behind it. With Jackson's 2014 piece Our Flags Are Waving With Hope and Grief, you could say to yourself, "I got it," and not delve into the piece's other dimensions. But by the end of the concert, there was a strong sense — whatever your politics — of "mission accomplished." And in no uncertain terms.