An accountant and father of two, Bob Galvin, 67, leads a quiet, unremarkable life with his wife in Plymouth. That is, until you get him talking about music. Then his superpowers come out.

For 25 years, Galvin has had a radio show on Provincetown’s WOMR called Charted Course that delivers Top 40 hits from the 1960s through the 1980s. He arranges every one of his shows around Billboard charts. Sometimes, he simply plays the top 40 songs from, say, 1975. But his encyclopedic mind often creates more complex combinations.

On a recent Thursday, for example, he played 35 songs from 35 years. The common thread? The order in which he played each tune matched its peak position on the charts for that year. The first song on his show was number 35 when it reached its top position, the following was number 34, moving all the way to number one.

Galvin’s playlists, being oft-played pop hits, are familiar to most of us. But the way Galvin puts them together adds layers of nostalgia, harkening back to the soundtrack of one’s life at a certain time. Anticipation builds over the three hours of Charted Course as you try to guess the next song. Since Galvin’s choices usually move from the lowest on the charts to the highest, listeners expect each song to get progressively better.

John Braden, WOMR’s executive director, said that Galvin has a “savant-like” ability with numbers. “That is my disease,” Galvin jokes. He has the same prodigious memory when it comes to baseball statistics and Oscar-winning movies.

Galvin’s musical passion started with Casey Kasem’s Top 40 show, which hit the Boston airwaves in 1970. Galvin was a teenager living in Dorchester. He would go to Harvard Square each week to buy the newest issue of Billboard, the official record of the weekly Hot 100 hits. He kept notebooks (now thrown away) to track the songs as they moved up and down.

“It’s funny, because I do accounting, and it’s sort of incorporated into my methodology,” he said. “Basically, I was doing accounting before I even knew what accounting was.”

At one point, Galvin owned about 2,000 compact discs and vinyl records. Now much of his collection is stored on his computer. He also owns numerous books on Billboard charts, many by Joel Whitburn, the leading authority on the subject. Galvin has absorbed all kinds of musical trivia that make for juicy anecdotes on the show.

Despite this teenage passion, Galvin never wanted to be a professional disc jockey.

Frank Foley, a former WOMR DJ known as Captain Frank, the host of Root Soup, recognized Galvin’s superpower and came up with his radio name, “Billboard Bob,” in 1995. At the time, both worked at the Sheraton in Eastham, where Galvin was an accountant. Foley invited Galvin on Root Soup as a guest. His entertainment value was immediately obvious.

The following year, Billboard Bob began his own show on May 30. There’s no doubt that date is right, as he has kept 14 notebooks that contain “every single song I’ve ever played” on every show.

Galvin said he can put together a show in one hour, though it usually takes a lot longer to listen to and savor each song. He called the Saturday ritual of creating the show “one of the most fun things I do.”

To test his knowledge, the Independent asked him what tune was No. 1 in June 1975. Bob thought about it for a second. At first, he came up with the top song in July of 1975: “The Hustle” by Van McCoy. He explained that there were 35 No. 1 hits in 1975, quite possibly more than in any other year.

This led Bob into a discussion of the Thriller album by Michael Jackson. It produced seven hit singles, he said.

But getting back to June 1975, Billboard Bob finally said, “I believe that, in June, ‘Love Will Keep Us Together’ by the Captain & Tennille was number one for four weeks and the number one song for that year.”

Galvin’s recall is impressive, but he is also forthcoming about his personal tastes. His favorite musical era? It was 1966 to 1975. Favorite song? “The Story in Your Eyes,” by the Moody Blues, which is his favorite band, followed in no particular order by the Beatles, Simon & Garfunkel, Tom Petty, Alice Cooper, Led Zeppelin, the Rolling Stones, and “I could go on and on,” he said.

If you want to hear more, Billboard Bob’s Charted Course is on the air every Thursday from 5 to 8 p.m. on WOMR, 92.1 on the FM dial.