Representative image. Photograph:( Zee News Network )
In selecting songs for their study, the researchers included those that reached the No 1 spot on the Billboard 'Top 100' between the years 1940 and 1957 and No 1 on the Billboard 'Hot 100' from 1958 to 2015.
Millennials are better at identifying songs made between the 1960s and 1990s than they are at recognising musical hits created from 2000 to 2015, according to a study.
"The 1960s to 1990s was a special time in music, reflected by a steady recognition of pieces of that era -- even by today's millennials," said Pascal Wallisch, an assistant professor at New York University in the US.
While the researchers did not identify what explained the stable level of recognition for songs from the 1960s through the 1990s, they note that during this period there was a significantly greater diversity of songs reaching the top of the Billboard charts compared to 2000 to 2015 and 1940 to 1950.
A large number of popular songs during the latter part of the 20th century may explain why so many are recognisable decades later, according to the study published in the journal PLOS ONE.
However, the researchers acknowledge that the findings could be the result of self-selection, there was a considerable correlation between the likelihood of recognising a given song and its corresponding play count on Spotify, which they also measured.
This result underscores the popularity of certain songs from the 1960s through the end of the 20th century, researchers said.
"Spotify was launched in 2008, well after nearly 90 per cent of the songs we studied were released, which indicates millennials are aware of the music that, in general, preceded their lives and are nonetheless choosing to listen to it," said Wallisch.
Researchers noted that recognition of songs even from this period varies.
Some were extremely well known, such as "When A Man Loves A Woman" by Percy Sledge (1966), and "Baby Come Back" by Player (1977) whereas others, like "Knock Three Times" by Dawn (1970), and "I'm Sorry" by John Denver (1975), are all but forgotten.
In selecting songs for their study, the researchers included those that reached the No 1 spot on the Billboard "Top 100" between the years 1940 and 1957 and No 1 on the Billboard "Hot 100" from 1958 to 2015.
The study's 643 participants included students as well as others from the greater New York metropolitan area.
The sample was largely of young participants, with a mean age of 21.3 years. The majority (88 per cent) of this sample was between the ages of 18 and 25.
Each participant was presented with a random selection of seven out of the 152 songs in the sample, asked to listen to the selection, and report whether they recognised it.
Participants were presented with 5-, 10- and 15-second excerpts deemed to be represented by a consensus panel of seven practicing musicians and professors of music theory and composition.
These excerpts often contained a highly recognisable "lick" -- a unique and often repeated pattern of notes played by a single instrument -- of each song.
In response to hearing each song, participants were prompted to indicate whether they recognised it. The researchers then plotted the recognition proportion for each song as a function of the year during which it reached peak popularity.
The results revealed three distinct phases in the collective memory.
The first phase showed a steep linear drop-off in recognition for the music from this millennium, steadily declining, year by year, from 2015 to 2000.
The second phase was marked by a stable plateau from the 1960s to the 1990s, with no notable decline during this 40-year period.
The third phase, similar to the first phase, was characterised by a more gradual drop-off during the 1940s and 1950s.