The five Oscar-nominated short documentary films for 2014 are a generally staid bunch, brie and white wine offerings less interested in exciting or enraging viewers than in teaching socially conscious lessons. Generally, I say, because the wan bouquet contains one absolutely gorgeous bloom. We’ll get to that dazzler shortly. First, the rest.

Alice Herz-Sommer, at 110, is said to be the oldest Holocaust survivor and oldest known active pianist, a vocation that helped sustain her spirit and possibly saved her life during her years in Hitler’s concentration camps. At the Czech camp Theresienstadt, prisoners with musical skills were spared, and involuntarily starred in propaganda newsreels that made camp life look cheerful. “I was thinking, when we can play, it can’t be so terrible,” she recalls. “Music brings us on an island with peace, beauty and love.” Given its themes, “The Lady in Number 6” is favored to win, but it is one-note filmmaking.

The same goes for the HBO-produced documentary “Prison Terminal: The Last Days of Private Jack Hall.” It’s a prosaic you-are-there account of an aged World War II veteran and convicted murderer in a maximum-security prison hospice. Once a violent segregationist, the old cuss mellowed considerably toward the end, as fond of his black caregiver-inmates as they are tender toward him. The matter-of-fact observation of Hall’s death, the moment when the human face at the center of the film is simply no longer there, delivers the sense of something once vital slipping into oblivion. It’s another story with profound implications but disappointing delivery.

“Karama Has No Walls” takes us inside the 2011 Yemeni uprising that left 53 dead in the capital city of Sanaa. The camera is pushed along in tidal surges of bodies amid a cacophony of chants, gunfire and screams. The shopworn take-away is that change sometimes comes at a terrible cost and that streets raked with sniper fire are no place for children. Duly noted.

“Facing Fear” is an elaborate public-service announcement for the Los Angeles Museum of Tolerance. Matthew Boger, an LAMT executive, was a gay street kid in West Hollywood 25 years ago. He was severely beaten in a homophobic street attack. Decades later he met his main attacker, now repentant, and the duo offer classes on intolerance and forgiveness. The half-hour film is the sort of thing you watch for extra credit in civics class.

Now, that good one I promised you: “Cavedigger.” It’s a portrait of New Mexico excavation artist Ra Paulette, who attacks mountains of soft sandstone with pick and shovel and trowel, creating sensual, cavernous spaces of light, air and wonder. Paulette’s glorious underground sand castles are staggering to behold, and director Jeffrey Karoff does them full justice with rapt, admiring camerawork. He also wittily captures the exasperating conflicts between the artist and his clients (and friends and wife). “Cavedigger” is an artfully composed love letter to artistic passion, and a must-see on a big screen.