Forest of violin playing trees in the land of Oz, from the 1923 young adult novel The Cowardly Lion of Oz by Ruth Plumly Thompson. It's briefly visited by the Cowardly Lion and his companions, Notta and Bob. At night, the seemingly ordinary trees pull violins out of their trunks (doh) and play sweet music.
Bob nodded, and at this a little rustle went rippling through the forest as if the trees had actually heard him, and in the same instant each tree quietly opened its trunk and drew forth a fiddle. Before Notta and Bob had recovered from their surprise a wave of music swept through the wood, now soft, now loud, but more entrancing than any they had ever heard. And the trees, swaying and bending in the dim starlight, plied their bows with more skill than any orchestra in the mortal world. For Bob and Notta, you see, had come to the Fiddlestick Forest of Oz.
Of all his adventures, Bob remembered this strange concert longest. The fairylike music, that even made the Moon bend down to listen, the drumlike accompaniment of Nick’s snores and the misty faces of the trees themselves, bending down in the dim starlight, all added to the enchantment.