Sustainable sound?

It is interesting to note how quickly sustainable has come of age.  More and more the media is filled with reports of all sorts of sustainable efforts in all walks of life.  Here is another unexpected contribution from a French music band and a swiss engineer on a world tour to promote the message of sustainable growth and development.  Their contribution?  A sound amplifier system manufactured from sustainable materials.  Their message?  Promote the need for a sustainable world, by providing their sound system on rent basis to Indian musicians.  What’s more, the system comes with its own battery source that can be charged with a solar panel, making it eco-friendly too.