BOSTON • The composer Gregory Brown describes himself as an introverted academic who prefers playing the piano or walking his dog to standing in the spotlight.
But you have probably heard of his older brother: Dan Brown, the author of blockbuster page-turners including, of course, The Da Vinci Code.
Gregory will not be able to hide for long, though. His brother's fact-heavy novels often send readers racing to Google and the latest book, Origin, devotes an entire chapter to one of Gregory's pieces: Missa Charles Darwin.
In the acknowledgements, Dan goes so far as to write that Gregory's "inventive fusion of ancient and modern in Missa Charles Darwin helped spark the earliest notions for this novel".
That "fusion" refers to the form of Missa Charles Darwin, which follows the tradition of five-movement Latin Masses, but substitutes much of the sacred text with excerpts from On The Origin Of Species and other Darwin writings.
The juxtapositions can be bracing, such as Kyrie eleison (Lord have mercy) followed by the brutal line, "Let the strongest live and the weakest die".
The piece may sound like Renaissance polyphony, but its score also nods to modern science, transcribing the DNA of Darwin's finches for the opening melody, for example, and adapting into musical variations genetic concepts such as insertion, mutation and deletion.
"There's this exploration of the edges of things," Gregory Brown said in an interview in Boston. "Whether that edge is science and music, or religious and scientific, or sacred and secular."
In a telephone interview, Dan Brown said he is "always looking for big themes" and when he first heard the mass performed in 2011 at the Marine Biological Laboratory in Woods Hole, Massachusetts, "it got me thinking about creationism and this sort of battle between science and religion".
He followed the idea until it became Origin, a thriller - starring his signature protagonist, the Harvard "symbologist" Robert Langdon - about a brazen scientist whose discovery about the source of life on Earth and the future of humanity threatens to upend the world's religious order.
Missa Charles Darwin appears late in the book, after a wild night for Langdon that begins with a clandestine encounter inside a Richard Serra sculpture and ends at a computing centre that holds the key to life's origins. He enters the centre and hears Gregory's "Christian-style mass", in which devout voices take their place alongside a celebration of natural selection.
"This piece of art that fuses science and religion and makes them beautiful - I thought at that point in the novel, it was just this moment when you needed to rest and see that these two can intertwine," Dan Brown said.
Dan Brown did not tell his brother that the mass had made its way into Origin until he finished writing the chapter.
He said that when he asked Gregory to give it a read - they are often sounding boards for each other - "he came back sort of wide-eyed". Gregory gave his blessing, with a slight correction to how the music was described.
Then he realised what kind of exposure this appearance in the novel could provide.
"Within 24 hours, wheels started turning for what this might do," Dan Brown said. In the end, any money his brother makes from New York Polyphony's recently reissued recording of Missa Charles Darwin will be donated to music education programmes.
Origin was released last Tuesday and Gregory Brown said he is bracing himself for whatever happens.
"When you're a composer, you write a piece and hope it gets one performance," he said. "When it gets two, you're lucky. But who knows what will come of this?"