A volincello is a string instrument that is a hybrid between a violin and a cello, designed to be played with a bow like a violin but tuned an octave lower, similar to a cello. It features a larger body than a violin, allowing for deeper tones, and is typically used in orchestral settings or chamber music. The volincello is less common than its counterparts and serves to bridge the tonal gap between violins and cellos in musical compositions.