The founder of a Los Angeles-based non-profit organisation which provides free music lessons to low-income students from gang-ridden neighbourhoods began to notice several years ago a hopeful sign: children were graduating from high school and heading off to the University of California Los Angeles and other big universities.
That's when Margaret Martin asked how the children in the Harmony Project were beating the odds.
Researchers at Northwestern University in Illinois believe that the students' music training played a role in their educational achievement. Martin noted that 90 per cent of them graduated from high school, while 50 per cent or more didn't from the same neighbourhoods.
A two-year study of 44 children in the programme shows that music training changed the brain in ways that made it easier for youngsters to process sounds, according to results reported in Tuesday's edition of The Journal of Neuroscience. That increased ability, the researchers say, is linked directly to improved skills in such subjects as reading and speech.
But, there is one catch: people have to actually play an instrument to get smarter.
Nina Kraus, the study's lead researcher and director of Northwestern's auditory neuroscience laboratory, compared the difference to that of building up one's body through exercise. "I like to say to people: you're not going to get physically fit just watching sports," she said.
Kraus said studies like hers were challenging because researchers needed to follow subjects for years in order to track changes in the brain. She said more and larger studies needed to be done in a variety of districts to "help us understand what are the most effective forms of learning and how might learning be tailored for an individual child".
The latest findings are striking a chord with supporters of such programmes who say music is frequently the first cut for school boards looking to save money.
"Over and over, we've learned that children need rich, multisensory environments, and learning music sort of brings all of that into a package for them," said Mary Luehrsen of the National Association of Music Merchants Foundation, which awards scholarships and research grants for the study of music, adding that the results make the point that music training should be an important part of all school curriculums.
April Benasich, a professor of neuroscience at Rutgers University who was not involved in the study, said previous research by Kraus demonstrated music improved concentration, memory and focus in children.
Benasich, who researches early brain development, said the study's findings were "a game-changer for both the scientific and public policy domains, particularly in an era when these sorts of enrichment activities are being aggressively eliminated from our schools".
Martin approached the National Institutes of Health, seeking to learn if there was a connection between music and the educational achievements of the programme's 2,000 students. The institute put her in touch with Kraus, who studies brain changes that occur through auditory exposure. Many of the project's students had no interest in pursuing professional music careers, Martin said.
Adelina Flores, whose 11-year-old daughter, America, was a test subject, said she wasn't surprised by the results. Her daughter had already told her she was getting better at maths because playing music had taught her to divide notes into fractions and count them out in measures.
"She's improved a lot through this," Flores said, adding: "And she's grown to be more confident too."