Here’s another tutorial, this time in the form of an Instructable, although it’s not for the ‘beginner’. It uses wires of different lengths, an accelerometer to detect different vibrations caused by plucking the wires and an MCP3008 analog-to-digital converter chip to translate the signals produced. These are fed into the Raspberry Pi which generates synthesized noises via ALSA based on the initial vibrations. The software is written in C. The tutorial is written in English and French and can be found here.