It’s a haunting sound when a group of boys’ voices in the treble range convene.

I’m not talking about performances by boychoirs, which feature the unchanged voices of prepubescent boys, who together make a sound so lovely and pure that the effect is haunting.

I’m talking about the start of boychoir practices and the scary sound created when a gaggle of rambunctious dudes with short attention spans and constant jokes get together to learn the craft of choir singing.

But for 30 years, the ever-patient Dr. Thomas Strode has led the Boychoir of Ann Arbor through innumerable practices, and his ability to keep cool and impart high-quality musical education to a rather wiggly and easily distracted audience is remarkable.

In the common area of Ann Arbor’s St. Paul Lutheran Church, where Strode is the director of music, he teaches boys musical theory and gives singing lessons using a quiet, measured tone of voice. Under Strode's gentle guidance, the boys' constant hum of silliness at the start of practice soon becomes a gloriously soothing sound when they begin to sing.

Strode instructs a prep choir, for newer singers, as well as the performing choir, which features more experienced vocalists and expands the treble boychoir model to also include an SATB (soprano, alto, tenor, bass) choir, with the older boys and their changing voices providing the lower notes.

Dr. Strode really understands how to teach children, which is why Boychoir of Ann Arbor has thrived for three decades. And the kids really do learn to sing beautifully, as listeners will be able to hear at the “A Boychoir Christmas” concerts on December 9 and 10.

These annual shows are highlights for many holiday concertgoers -- but they will also be Strode’s final ones as the choir’s director. He’s retiring at the end of the boychoir’s season, which wraps on June 4 with the “Spring Finale” concert.

With this being Strode’s final Christmas concert, we asked the good doctor to give us a preview of what we will hear and why.

Do you have a God complex? Then documentary filmmaking might not be for you.

“In feature films the director is God; in documentary films, God is the director,” said the deity Alfred Hitchcock.

But the seven documentaries being shown in Ann Arbor this December had directors who put aside any supernatural ambitions they may have to tell real stories.