They’re still finding music by Mozart, so should we be surprised that a work written by Ralph Vaughan Williams, who died a mere 50 years ago, is getting its world premiere?

On Saturday, the Cathedral Choir and Cathedral Choral Society at St. Mark’s Episcopal Cathedral in Minneapolis will give the first performance of “Vexilla Regis,” a work the British composer wrote in 1894 when he was a 22-year-old music and history student at Cambridge University.

The existence of the work, an undergraduate composition exercise, is not a new discovery. It’s been part of the Cambridge library’s manuscript collection for some time. Choir member Dave Fielding, who has an interest in finding neglected choral music, came across “Vexilla Regis” when he was looking through a list of Vaughan Williams works organized by music critic and biographer Michael Kennedy.

That led to negotiations with the Ralph Vaughan Williams Estate, which allowed Fielding to receive a digital copy of the 84-page manuscript (it helped that the Cathedral Choir’s music director, Raymond Johnston, is a Cambridge graduate).

“In one way, we were actually very lucky,” Fielding said. “Vaughan Williams was noted for bad penmanship, and I was dreading trying to decipher his handwriting. But fortunately for us, he had employed a copyist in 1894, so it was extremely legible.”

Fielding and Johnston prepared the performance and instrumental scores using Finale, a leading software program made by Minnesota-based MakeMusic.

So on Saturday, the world will hear something new from Vaughan Williams. Also on the 7:30 p.m. program is another Vaughan Williams work (from 1938), “Serenade to Music,” as well as the familiar Haydn “Missa in Angustiis” (Mass for Troubled Times) that is more popularly known as the Lord Nelson Mass after Horatio Nelson, hero of the Battle of the Nile on Aug. 1, 1798. The Mass got its first performance a month or so later.

For tickets, go here.