Here’s a great idea for the eco-friendly music aficionado with plenty of time on their hands. Forget making matchstick models of ships in bottles, how about painstakingly creating a giant wooden glockenspiel inside a forest.

This is what Japanese mobile giant NTT DoCoMo recently did as part of an advertising campaign for its limited edition Touch Wood, back to nature-style, handset.

The mobile manufacturer constructed a mile long wooden marimba instrument in the heart of a forest, enabling a wooden ball that traversed the structure to play out a gentle, melodious version of Bach’s ‘Jesu, Joy of Man’s Desiring’.

Just how many felled trees it took to construct the eco-friendly, minimalist iPod is open to question. However, it’s certainly a refreshingly peaceful piece of ambient advertising in the increasingly cluttered, chaotic and bombastic mobile marketing sector.