Name that Christmas tune and Ronald M. Clancy knows the story of its origin. He'll mention the composer and often the lyricist, arranger, or artists who have performed it. Pressed for more details, he'll reveal the label, estate, or recording company that holds the rights to the song. And he might even describe a great painting that he thinks captures its spirit.

The Christmas-music historian, who lives in Lower Township, N.J., when he's not delving into library stacks around the country, is the founder of Christmas Classics Ltd. in Cape May, a company that sells thoughtfully compiled packages of holiday CDs, bound sheet music, and finely illustrated companion books. His deeply researched texts trace the expanse of "joyful noise" from the early Renaissance mystery plays to Broadway and beyond.

In the season when all those of goodwill are asked to have faith, it's troubling to think that Clancy, who appears to be a merry guy, spent a Dickensian childhood in a Philadelphia orphanage. Now 68, he was neglected as a baby and raised by the nuns of St. John's Orphan Asylum. One Christmas Eve, when he was a first grader, he was roused from his sleep and marched with the other children across a wintry courtyard into the grandly illuminated chapel.

"Tethered to the pillars were all these balsam trees, a very fragrant smell in the chapel. And a big creche on the altar," recalls Clancy, who was mesmerized by the harmonies of the nuns as they proceeded through the repertoire of carols. "It was a wonderful feeling. It was my first midnight Mass."

His beloved nuns shepherded the young choirboy through grade school and high school. A graduate of the journalism program at George Washington University, Clancy worked as an executive recruiter for many years in Philadelphia. He's been married to Renate, a retired schoolteacher and chief supporter of his so-called quixotic dream, for the last 21 years.

The Rev. Bates Burt of Michigan, a noted composer of Christmas songs in the 1920s, began a family tradition of tucking compositions into his holiday greeting cards. Clancy's fascination with carols flourished in a similar way. Drawing on his personal collection of seasonal music - a considerable library by the late '80s - Clancy gave cassettes as gifts, wrapping them with typed index cards containing brief descriptions of the recordings and other minutiae. His friends' response encouraged him to dig further.

Best-Loved Christmas Carols, Clancy's first book/CD combo, was released in 2000, followed in the next two years by American Christmas Classics and Children's Christmas Classics. Clancy spent years wrangling copyrights for recordings, artwork, and lyrics, paying out of pocket and decimating his savings. (A contract with Sterling Publishing Co. helped stabilize his finances and produced a new version of Best-Loved Christmas Carols in 2006 and Sacred Christmas Music in 2008.) American Christmas Classics, for instance, required 172 clearances, 91 of which were for art reproduction. Five images of Norman Rockwell paintings alone cost about $400 each.

Some songs took him on journeys of knowledge, such as the 16th-century "Coventry Carol," whose genesis is found in biblical mystery plays. Because it was written as a mothers' lament following the infanticide ordered by Herod in Bethlehem, Clancy decided he needed female voices and obtained rights to a recording by the women of the Norman Luboff Choir. In the accompanying book, he illustrated his passage about the carol with Alessandro Turchi's 17th-century painting The Massacre of the Innocents.

"The Philadelphia public library? I was permanently parked there," says Clancy, remembering the 300-plus hours he estimates were spent in the main branch. "Most of the time in their music department."

Other songs took him on literal journeys. During a 4,200-mile road trip in 2008, Clancy was able to visit and document sites associated with many famous American carols, such as "Jingle Bells" (Savannah, Ga., and Medford, Mass.), "Mary Had a Baby" (South Carolina), and "I Wonder as I Wander" (North Carolina). His adventures, captured in stills and on video, provided the thread for the "Christmas Classic Chronicles," a 22-episode travelogue that can be seen at christmasclassics.com. The chronicles are narrated by Brad Walton, now deceased, a radio personality on WCCO, Minneapolis; Clancy had become a seasonal fixture on Walton's show.

As Clancy toys with new media, he likes to marvel that he launched his project with LPs instead of CDs, index cards and pencils instead of Excel spreadsheets, and hand-typed letters instead of e-mails. His efforts to track down a '50s-era illustration for the story of "Silver Bells" involved seven hours of sifting through old Life magazines in the Library of Congress.

" 'Silver Bells' was the first song really about Christmas in the city. Most have a rural feel to them," he explains. The author eventually found a Pacific Mills ad for cotton fabrics that depicted a city block bustling with holiday shoppers and a bell-ringing Santa.

Clancy's favorite hymns are "O Holy Night (Cantique de Noël)" and "O Little Town of Bethlehem," but he's also a big fan of Nat King Cole, who famously recorded "The Christmas Song," also known as "Chestnuts Roasting on an Open Fire" and "Merry Christmas to You." (Interestingly, that 1940s tune was cowritten by Mel Tormé and Bob Wells during a sweltering West Coast summer.)

However, Clancy adds, some of the best-crafted carols are pure and simple, passed orally throughout the Middle Ages, their composers lost to history.