John Granzow saw a bin full of discarded coffee portafilters and began to hear music. The form reminded him of the frame for a tiny banjo and he set out to see if the connection could be more than visual. Using 3D software, he created CAD files for the soundboard and fret work that he has shared as STL files on Instructables for his creation, the Javalele. For anyone who doubts the possibility of something so small being turned into an instrument, he has even included a short demo of his 3D print converting something discarded into something melodic. Check out the video, and more details, in the full article:

Below is a photo of the 3D printed Javalele: