SOLVED. Picture book about a fisherman who befriends several musician cats [s]

[Erin]

Solved thanks to Ayshe! It's Old Robert and the Sea-Silly Cats, which is amazing considering how many things I got wrong—the cats are singing, dancing, and juggling, not playing instruments, and it's a Dutch illustrator, not a French author. Such a delightful book.
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I'm looking for a children's picture book from the last 10-15 years or so about a fisherman who lives alone on his boat until he is slowly joined by a series of cats, each of which plays a different musical instrument. The moon is also prominent. I think the author may have been French, but the edition I read was in English. Thank you!

[Tab]

What type of instruments did the cats play?
Anything about the cover?
Part of a series?

Were the illustrations colorful, realistic, full page, etc?

[Erin]

I don’t remember which instruments, but the illustrations were colorful, I think either paintings or maybe oil pastels. Most of the book takes place at night, so the overall palette had lots of deep blues.

[Ayshe]

Old Robert and the Sea-Silly Cats maybe?

[Erin]

AYSHE YESSSS thank you so much!