Who knew that the most important qualification for performing onstage with The Atlanta Symphony Orchestra was not one’s musical expertise, but the color of one’s skin?

Who knew that the defining characteristic of its performances was not the sound it produces, but the complexions of those who grace its stage?

Indeed, who knew that those who run the Orchestra were so enslaved by political correctness?

The ASO hit a discordant note when it was learned last week that it had given the hook, so to speak, to the student choruses at two of Cobb’s finest high schools, Lassiter and Walton, which have regularly performed with the Symphony in recent years.

The pink slip came not because they couldn’t sing well enough and not because they couldn’t handle the material, but because of their complexions. Or in other words, because they were too pale. The student bodies at the two schools are each more than 75 percent white, a fact no doubt reflected in the makeup of the two choruses as well. The two public schools do not pick and choose who attends, but offer education to one and all. Their student bodies, for better or worse (definitely worse, in the eyes of the ASO), are reflective of the neighborhoods they serve.

The two choruses had performed with the Orchestra for the past four years but announced on Monday to students that the ASO had decided to “go in another direction.”

Lassiter Choral Director Brian Williams and Walton Choral Director Dr. Jana Williams said they’d been told by Symphony officials that it was going to invite choruses from other schools instead. Why? Because the other choruses that were to be invited were “more diverse,” the Cobb officials said.

That’s not how the ASO played it for public consumption, though. Vice President Charlie Wade said there are other top-notch choruses that deserve the opportunity to sing with the symphony.

Featured this coming holiday season will be the chorus from majority-minority Grady High School in Atlanta, he said. We think the Symphony is right to showcase young talent from the metro area, and to “share the wealth” in terms of who it allows to perform on it stage. But making such decisions based on a real or imaginary “color line” is shameful. We wonder how members of the Grady chorus must feel to know that even though they are highly talented, a main reason for their selection — perhaps the main reason — was not their ability, but their color?

The ASO offered a face-saving invitation of questionable sincerity, offering to let a few of the students from the two Cobb choruses sing as usual, but adding there would not be enough space onstage for both full choruses and Grady.

To their credit, the two schools told the ASO that it was everybody or nobody.

The bottom line? The ASO apparently felt its patrons were offended by the sight of so many white singers at past performances. We wonder if it is making similar purges of its string section, horn section, percussionists, etc.

So it looks like the ASO holiday concerts will come off without the participation of the choruses from Lassiter and Walton. Those who run the ASO, it seems, judge its singers by the color of their skin, not by the quality of their voices. And as far as we’ve ever heard, one’s ability to sing is in no way connected to one’s pigmentation.

We don’t think that’s quite the dream that the Rev. Dr. Martin Luther King Jr. had in mind.