David Cherwien has a theory he's borrowed about why there is a centuries old human fascination with deep vocal sounds.
"One of my mentors, Alice Parker, talks about this as being a characteristic that surprisingly comes out of oppressed cultures," he says.
Alice Parker is an American composer and conductor.
Cherwien is music director and conductor of the Minneapolis-based National Lutheran Choir. There's no scholarly support for his theory. But there's some circumstantial evidence.
Consider the Tuvans in Siberia.
Before Tuva's independence, China, then Russia, then the Soviet Union took advantage of their remote neighbor. Tuvan throat singing by the group Huun Huur Tu features lots of low notes but who knows? Maybe the tradition is born as much from the isolation of herding reindeer as from oppression.
The theory gets a bit more support closer to home with the Fairfield Four and bass Isaac Freeman. It's much easier to imagine a link between their music which features Freeman's remarkable range and the oppression of slavery.
How does the theory of oppressed cultures' fascination with the mournful sound of low voices express itself in Russian music?
For centuries Russians suffered under one lethal batch of leaders after another. Many found refuge in the church. On Sunday in Minneapolis the State Symphony Capella will sing liberal doses of Sergei Rachmaninoff's music. He composed plenty of choral music where he often sent the low voices into the vocal root cellar.
Russian sacred choral music conjures an image of people gathering to try find some comfort and hope in their Orthodox houses of worship, according to David Cherwien.
"I think we get images of these wonderful open mysterious spaces, probably dark, although that may be a stereotype with incense and icons, and the music represents that sense of mystery."
Russian church music for a long time seldom reached ears outside the country.
Part of the reason was a tiff in 1054 between religious leaders in Rome and Constantinople over what language to use in the church helped bottle up and isolate the eastern music tradition from the west, Cherwien says.
One reason it has taken so long for Russia's premier chorus to come the United States can be traced to the former Soviet Union.
Soviet arts bosses controlled the destiny of artistic groups, says Leonid Flyshacker, a New York producer who helped arrange the choirs' U.S. tour.
"They were in command to say who is touring where and why," he says.
When the Soviet Union disintegrated 16 years ago, the USSR Chamber Choir became the State Symphony Capella and traveled the world.
In Minneapolis they'll share the stage with the National Lutheran Choir. The two choirs will perform separately, and then they'll stand together, all 120 voices, to sing a couple of tunes including a famous one, Pavel Chesnokov's song praising the Virgin Mary. The piece got a makeover and a new title in the West, "O Lord God," to make it palatable for Protestants.
The combined choruses will sing the Chesnokov composition as written in Russian.