What it really was, behind the effect we call “music”
Introduction: Parents Who Play Music for Babies
Pregnant parents play classical for prenatal stimulation. Once the baby arrives, the “Mozart effect” gets a slot in the playlist. Lullabies are replaced with background music. A bit later come the children’s songs and YouTube channels.
Somewhere along the way, parents have absorbed the idea “don’t keep the baby’s room too quiet.” This is especially true for parents of preterm babies — children born early are at higher-than-average risk for language and cognitive delays, so the urge to “do anything that might help” runs strong.
But does this “musical environment” actually help? If it does, what kind of music, given how? A 2024 paper from a Helsinki team gave a fairly specific — and slightly surprising — answer.
The Core Research Question
The researchers didn’t simply ask “is music good for preterm babies?” They drilled down:
“Which home music and language activities done together with parents predict language ability in preterm children at ages 2–3?”
Three specific hypotheses were tested:
- Does the quality of the home music environment correlate with preterm children’s language, cognitive, and motor scores?
- Does structured music programs (e.g., music play schools) have an independent effect?
- Does passive listening to music produce the same effect as interactive music activities?
How the Study Was Done
Participants
The team followed 45 babies born preterm at a Finnish university hospital.
- Gestational age: 24–34 weeks (mean 30.3 weeks)
- Assessment age: corrected age 23–38 months (mean 28.4) — corresponds to age 2–3 if full term
- No matched full-term control group: variation within the preterm sample was studied; comparisons were made to existing norms
Home music and language environment
Parents reported the weekly frequency of these activities through a questionnaire:
- Singing with the child / reading books to the child in the same room
- Playing instruments together / child playing instruments alone
- Listening to recorded music (including background music)
- Listening to live music (family playing music, etc.)
- Music play school participation
The key methodological choice: these activities were separated rather than rolled into one composite. Instead of asking the abstract question “how rich is the music environment,” the team asked which specific kinds of music activity actually mattered.
Child outcomes
The standard developmental measure Bayley-III (Bayley Scales of Infant and Toddler Development, Third Edition) was used to assess three domains:
- Cognitive ability (n=45)
- Language ability — receptive (understanding) + expressive (speaking) (n=43)
- Motor ability (n=40)
Results: Several Results Defied Expectations
Only two activities predicted language scores
In the regression, only two of the weekly activities significantly predicted preterm children’s language scores:
- Singing and reading to the child in the same room (t=2.647, p=0.012)
- Playing instruments together, or letting the child handle instruments (t=2.611, p=0.013)
The full model R² = 0.354 — about 35% of the variance in language scores was explained by these activities. With a small sample (n=43), that is a substantial effect.
Activities that had no effect
In contrast, these activities had no significant association with language scores:
- Listening to recorded music played in the room (background music)
- Listening to live music passively
In other words, whether Mozart or a children’s-song CD, just-letting-it-play music exposure was not connected to language development.
No effect on cognitive or motor scores
Music and language activities only predicted language scores. Cognitive and motor scores didn’t show meaningful associations. This contrasts with the popular belief that “music makes the whole brain smarter.”
The Music Play School story — an honest finding
In the initial analysis, music play school attendance appeared associated with language scores (p=0.03). But the team didn’t stop there. They added mother’s education to the model and re-ran the analysis. The independent effect of music play school disappeared. Mothers with more education tended to enroll their children in play school, and those children’s language scores were already higher because of the surrounding context.
One additional, encouraging finding
The team also noted that these preterm children scored on average close to the full-term norm on the Bayley language assessment. Given the risk that preterm birth carries, it is plausible that interactive home music activities contributed to that “catch-up.”
Why Did Only “Together” Matter — Music Isn’t the Medicine, Interaction Is
The most interesting point in the study is this contrast. Same “music,” but the form makes the result split sharply.
The team’s interpretation:
Beyond the auditory stimulation of music itself, social interaction is the core ingredient of language learning. Singing and playing instruments together involves eye contact, turn-taking, rhythm-matching, shared affect — every element of two-way communication.
Put plainly: when a child learns the new word “apple,” the best context isn’t the word streaming from a speaker. It’s someone watching the child’s reaction and saying “Apple! Want some apple?” while the child responds. Music just adds rhythm and joy on top of that interaction. Music itself isn’t the engine of language development.
This interpretation matches a long-established principle of infant language development: language input embedded in social context is the most decisive factor. This study shows that the same principle applies identically to preterm infants.
The Music Play School finding carries a parallel message. It isn’t expensive programs and specialist classes that perform magic. What’s likely going on is that the surrounding interactions in the families that attend such programs are doing the work.
Practical Implications
Don’t play it — sing along
Playing classical through speakers and singing alongside your child are, from a language-development standpoint, completely different activities. The clearest message of the study. Pitch and tone don’t have to be perfect. What matters is making sound together, responding to the child, matching rhythm.
Instrument play is language stimulation, not music education
Playing instruments together, or responding when your child taps a toy xylophone — that is what correlated with language scores. Not for music school, but for the kitchen with a wooden spoon and a pot.
A hopeful message for parents of preterm babies
When parents of preterm children worry “is my child falling behind?”, this study offers a relatively simple, doable answer. Not expensive early-intervention programs — a few minutes a day, at home, of singing and reading can contribute to bringing a preterm child’s language to full-term peer level.
Question the “magic” of programs
Whether expensive programs like music play schools do their work through the program itself, or through the family environment that chose the program, has to be separated. This study’s honest answer leans toward the latter.
Limitations
The team noted:
- Small sample (n=45), limiting statistical power and subgroup analyses.
- No full-term comparison group. Only within-preterm variation was analyzed.
- Parent self-report. Actual time spent and quality of activities couldn’t be measured objectively.
- Observational, not experimental. Causal claims aren’t possible. Families with high “interactive music activity” likely have other unmeasured positive characteristics.
- Highly educated sample, limiting generalization.
- COVID-19 impact on assessment timing and conditions.
- Results focus on very-to-moderately preterm (≤34 weeks); late-preterm generalization is uncertain.
Closing
The message of this study is clear and humble:
What helped preterm babies’ language development wasn’t “music itself” — it was the parent-child interaction that music carried.
Classical playing in the background does not grow a brain on its own. Instead, the few minutes when a parent sings beside their child, or responds to the rhythm a child taps on a toy instrument — these ordinary, small moments brought preterm babies up to peer level.
The good news is that this is something any parent can start today.
Source: Kostilainen, K., Fontell, N., Mikkola, K., Pakarinen, S., Virtala, P., Huotilainen, M., Fellman, V., & Partanen, E. (2024). Music and reading activities in early childhood associated with improved language development in preterm infants at 2–3 years of age. Frontiers in Psychology, 15, 1394346. https://doi.org/10.3389/fpsyg.2024.1394346