Which term refers to "left hand" in musical instructions?

The term that refers to "left hand" in musical instructions is "mano sinistra." This Italian phrase directly translates to "left hand," and it is commonly used in sheet music to indicate that the performer should use their left hand for playing the indicated notes or passages. In various musical contexts, particularly for keyboard instruments, it is essential to specify which hand to use, especially when performers are playing complex pieces that require coordination between the hands.

The other options pertain to different musical instructions or techniques. For instance, “marcato” indicates a particular articulation style, signifying that a note should be played in a marked or emphasized manner. “Martellato” refers to a type of bowing technique for string instruments that produces a strong, accented sound. “Mano destra,” on the other hand, means "right hand." These terms, while relevant to music, do not convey the meaning of "left hand," clarifying why "mano sinistra" is the appropriate choice.