A three-year study of more than 200 children aged under five found that attending weekly music classes for 10 weeks could close developmental gaps of as much as six months.
The findings also suggest musical interventions could help children improve their speech, self-confidence and ability to listen.
Charity Soundabout delivered the music sessions in 27 children's centres and local organisations across England from 2015 to 2018.
All the 216 children were considered to be from areas of high deprivation, while 16 per cent had complex needs such as profound and multiple learning difficulties.
The charity assessed the children's musical development using a standard of "age-related expectations". This indicated levels of musical development a child should achieve at certain ages, based on previous studies.
Researchers also considered three areas of musical ability: reactive, which involved listening and responding to music; proactive, which required the child to make music alone; and interactive, which involved them engaging in music-making with others.
At the outset, the 182 children without complex needs showed delays of six months compared with non-deprived peers in the reactive domain, nine months in the proactive domain, and nine and a half months in the interactive domain.
By the end of the course, the reactive category delay had been closed completely, while the proactive ability area had reduced by five and a half months, and the interactive delay reduced by four months.
- Good Practice: Music in Mind
- The Effects of Mother-Infant Singing on Emotional Closeness, Affect, Anxiety And Stress Hormones
For the 34 children with complex needs, who had a mean age of three-and-a-half and a musical developmental level of about six months, the sessions helped them to move up to a developmental level of 18 months in the reactive domain, and 12 months in the proactive and interactive measures.
The report states: "It appears that the rate of change is more rapid than that made later in childhood.
"It may be that children with complex needs in the early years have a greater neural plasticity than that found later in childhood, as is the case with their able-bodied peers."
The study also found linking everyday language to simple melodies had a positive impact on children with language delay.
Researchers noticed improvements in the children's ability to listen and pay attention in sessions, as well as helping them develop self-confidence and self-awareness.
Soundabout chief executive Clare Cook said the finding showed music could make a "real difference" to children's lives.
"The legacy of this fully inclusive early years project is powerful evidence that every child in the UK (and beyond) should have the right to access to music, both for its own sake, and to support their wider development," she said.
Although the Early Years Foundation Stage, states that educational programmes for under-fives must include music, Soundabout's project director and professor of music at the University of Roehampton Adam Ockelford said more emphasis is needed.
"Music really is brain food that can nurture children's development and wellbeing in a way that nothing else can," he said.