New parents might want to put a pint-sized tambourine in their babies' hands and start them shaking. A new study has shown that musical playtime improves the way 9-month-olds' brains process both music and speech, and could have a positive effect on infants' development of cognitive skills in general.

At the heart of the study is the importance of perceiving rhythmic patterns, which both music and speech have in spades. Listeners use the timing of syllables to differentiate one speech sound from another, explains CBS News.

"Infants experience a complex world in which sounds, lights, and sensations vary constantly," said Patricia Kuhl, co-director of the University of Washington's Institute for Learning & Brain Sciences and a study co-author. "The baby's job is to recognize the patterns of activity and predict what's going to happen next. Pattern perception is an important cognitive skill, and improving that ability early may have long-lasting effects on learning."

It's hard to talk about kids and music without circling back to the Mozart effect: the popular idea that listening to classical music makes people, and babies in particular, smarter. The concept was introduced by a study in Nature in 1993, and it caught fire in popular culture — Baby Mozart videos, anyone? In 1998, Georgia Gov. Zell Miller even asked that the state budget include funding so that every newborn could be sent a CD of classical music. But scientific studies since then have been mixed in their conclusions and, on balance, doubtful that the phenomenon even exists. ("Mozart Effect, Schmozart Effect," was the title of a 2010 article in the journal Intelligence.)

The latest finding could be characterized as a win for the pro-Mozart camp — at least when considered as part of this broader question: Does music have a positive impact on infants' brain development? Significantly, the research focused on the effect of babies' participation in musical activities, not of passive listening. The study was published in the Proceedings of the National Academy of Sciences.

"Our study is the first to demonstrate that a type of enriched experience with sound other than language can influence infants' speech sound processing," lead author Christina Zhao, a postdoctoral researcher at the institute, told CBS News. "This is also the earliest age to our knowledge that music experience has been demonstrated to have effects that extended to speech processing."

The experiment worked like this: Over four weeks, 39 babies attended a dozen 15-minute play sessions with their parents. Twenty were assigned to a music group, and the rest to a non-musical group. (All were from homes where only English was spoken, and none had parents who were musicians.)

In the first group, recordings of children's songs were played while the parents — led by a researcher — helped their babies shake maracas or tap their feet to the beat. The babies were also bounced in time with the rhythm. The songs were in triple meter, like a waltz, which the researchers chose because of its difficulty level and lack of resemblance to human speech ("Take Me Out to the Ball Game" was among the selections).

The second group's play sessions involved only toys, albeit ones that required coordinated movement like cars and blocks. The researchers emphasized that both groups played in a social way that required their active involvement and body movement — "all characteristics that we know help people learn," Zhao said. Music was the only difference.

At the conclusion of the four-week study, the babies were brought back to the institute so their brains could be measured using magnetoencephalography (MEG) — a non-invasive technique that can provide measurements of ongoing brain activity and identify which part of the brain the activity is occurring in. Each baby listened to a series of music and speech sounds, played in a rhythm that was occasionally disrupted.

As compared with the toy group, the music group showed stronger brain responses to the disruptions in both music and speech rhythm. (In other words, they noticed the mistakes.) The disruptions registered in both the babies' auditory and prefrontal cortexes — regions that are important for cognitive skills, such as controlling attention and detecting patterns. It all adds up to the suggestion that participating in the musical sessions improved the babies' ability to detect patterns in and make predictions about sounds — a skill that's essential to develop when learning to talk.

The researchers noted that the parents' helping their kids move was a key part of the study. "We think babies learn the best when engaged in interactions with their parents," Zhao told The Week in an email. "Parents are babies' first and favorite toy."

As for the music itself, does it matter if you play a waltz or "Welcome to the Jungle"?

"All music involves patterns, so the effects we see in the baby brain could hold true for all music," Kuhl told Medical News Today.

Sing it, Axl.