Japanese and English language folk songs evolved in the same way

Japanese folk songs evolved in the same way as English language ones even though they are sung in different tones and scales.

Patrick Savage at Keio University in Japan and his colleagues analysed the musical notation of more than 10,000 folk songs, including the well-known Child Ballads from the pre-20th century. Around 4125 of the songs were sung in English and 5957 were Japanese.

The team defined a folk song quite loosely. “There are a lot of definitions, but we essentially said a folk song is an old song that has been orally transmitted between generations,” says Savage.

There are a few differences between Japanese and English folk songs. For example, Japanese folk songs use a five-note musical scale, whereas English ones typically use a seven-note scale. They are also quite different tonally.

The researchers, however, were looking specifically at how the two musical genres evolved and whether there were any similarities. They first converted the musical notations into letter sequences that could be read by an algorithm that usually tracks evolutionary changes in nature. “This algorithm can identify highly related pairs of melody,” says Savage.

The nature of the subject matter influenced the analysis. “It is difficult to tell which version of a song or which style of melody came first,” says Savage. This means that when the researchers compared two similar songs, they couldn’t say for sure whether a difference in the number of notes between the two was due to an insertion or a deletion – so they treated all of these sorts of changes as the same.

They could, however, distinguish insertion/deletions from note substitutions, where the number of notes in a melody is the same in two songs, but a given note has a different value in each song.

The researchers found that these note substitutions were less likely than note insertions or deletions in both Japanese and English folk songs. “We think this is because note insertions or deletions don’t really affect the melody too much,” he says. “Substitutions, like singing everything in a lower note, obviously messes up the melody a lot more.”

What’s more, the effect was stronger in Japanese songs. “Ornamentation is a bigger deal in Japanese folk songs,” says Savage, referring to when small, rapid changes are made to non-essential notes in a melody.

The team also found that musical notes that played a bigger role in a song’s melody were less likely to change as the ballad evolved. “The way the music is being transmitted – whether they are Japanese or English – is very analogous,” says Savage.

“The patterns of change documented in this study will come as no great surprise to musicologists,” says Marisa Hoeschele at the Acoustics Research Institute in Austria. “But it is interesting that these same constraints apply cross-culturally.”

“Studying how folk music evolved can lead to insights into how cultural evolution occurs more generally,” adds Hoeschele.

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