Musical gift for a toddler

Some friends are visiting the UK from New Zealand next month, with their little boy who will be 4 years old later this year.  Has anyone any suggestions for a musical present for him?  Bearing in mind luggage considerations – preferably something that’s not very big and not very heavy.

I didn’t find the right solution from the Internet.

References

http://www.abrsm.org/forum/index.php?showtopic=60837

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