Strumstick and Guitar Duet

Today I'm staying  on a musical theme during Perthshire Amber Festival. I'd never heard of a strumstick till my daughter added it to her repertoire of stringed instruments. Historically it is related to the dulcimer. According to the blurb you can't play a wrong note. When you begin, you fret the 1st string with one finger, and strum all three strings with a pick. Anywhere you fret the 1st string sounds good, and the other two strings make a background chord automatically!  Here she is accompanying her husband Rikki. Location: Timeshare lodge at Dunkeld.