A university professor in Tokyo says he has found the original version of a song that is often sung at graduation ceremonies in Japan in a music book published in the United States in 1871, clearing up a long-standing mystery about the song's origins.

Masato Sakurai, a professor emeritus at Hitotsubashi University, said the melody and fermata musical notations of the original "Song for the Close of School" are exactly the same as the Japanese school song "Aogeba Totoshi," which bids farewell to teachers and the years spent at school.

The words of the U.S. song were written by T.H. Brosnan and the music by someone known only as H.N.D., but there is little information about them, according to Sakurai, 67, who researches English philology as well as folk songs from Britain and the United States.

Sakurai has been conducting research on the original versions of school songs over the past 10 years and found the entry for "Song for the Close of School" earlier this month when he was looking at classic songbooks and carols.

The original song is about saying goodbye to friends and classrooms, according to Sakurai.

"There were no documents in Japan to help us track down the origin of the song and it is no longer known in the United States," Sakurai said. "I hope more will be found out (about the song and the writers) in the future."