In my book, Making Poor Man's Guitars, I show how to make a microphone from a beer can, Mason jar lid and piezo elements. This project is even easier than the beer can mic!
The mic is perfect for blues harmonica or lo-fi vocals...and all you need is an old handset and guitar jack. If you make one, post pics and vids below!
Parts needed:
Old telephone handset. (The one in this video is from the 1980's) 1/4" guitar jack Soldering iron and solder