What is what key is a violin in?

A violin is typically tuned to the key of G. This means that when the open strings (G, D, A, E) are played, they produce the notes G, D, A, and E respectively. However, the violin is capable of playing in other keys as well, through the use of finger placement and techniques such as shifting and modulation. The key of G is a popular choice for violin music, as it allows for a rich and bright tone.