What notes can violin double stop?
The strings must, of course, be next to each other, so the only options available with this kind of double stopping is G and D: ...and A and E: A surprising number of composers make use of this type of double-stop, because it is easy to play and the open strings give a very clean and resonant sound.
What is the stop on a violin?
In music, a double stop is the technique of playing two notes simultaneously on a stringed instrument such as a violin, a viola, a cello, or a double bass. On instruments such as the Hardanger fiddle it is common and often employed. In performing a double stop, two separate strings are bowed or plucked simultaneously.