Musical ability is biologically linked to literacy, a US study has found.
Children who performed well in reading tests were also good at discerning rhythm and tone, say scientists.
They also did better than average in tests of verbal memory.
Music skill accounted for 38% of the variation in reading ability between children.
Literacy and musical aptitude shared a common origin in the brain, the study showed.
The results may help to explain previous research suggesting that musical training can improve word skills.
"Both musical ability and literacy correlated with enhanced electrical signals within the auditory brainstem," said study leader Dr Nina Kraus, from Northwestern University in the US.
"These results add weight to the argument that music and reading are related via common neural and cognitive mechanisms and suggests a mechanism for the improvements in literacy seen with musical training."
A total of 42 children aged eight to 13 took part in the research.
Of these, eight were classified as "good readers" and 21 as "poor readers".
The children were tested on their ability to read and recognise words. Other tests looked at how well they could distinguish between different rhythms and tones.
Electrical measurements showed the brains of poor readers were less able to respond to regular, rhythmic sounds than good readers.
Musical aptitude correlated with reading performance. When rhythm and tone responses were measured separately, rhythm had the greatest effect. But the link with reading was greatest when the scientists measured both kinds of musical response together.