Rocking Stainless is a string instrument using a flexed stainless steel sheet resting directly on the strings as a sound radiator. It can work with a pickup, but for this video the sound was recorded acoustically (using a tiny digital recorder hidden behind the instrument). For more instruments by Bart Hopkin, visit the instrumentarium at www.BartHopkin.com.
And by the way! Bart has recently released an album of his music, made primarily on instruments he's made. It's called Audiorium, and it's available through the usual download and streaming services.