Sound and Music

Earlier this week I was reading about experiments made by Nikolai Tesla including theories of transmitting electricity wirelessly over great distances using resonances in the Earth's magnetic field. There are also theories that this effect caused the Tunguska event.  This lead to finding a fantastic blog (lots of interesting uses of sensors, field recordings, DIY tips and unusual microphone techniques), featuring recordings of magnetic fields (including the that of Earth).  This is was done by capturing data from magnetometers and processing the data usign a signal analysis program called baudline (free, but not open source).