What is typically indicated by a key signature in sheet music?

A key signature in sheet music serves as a guideline for the set of sharps or flats that will be consistently applied throughout a piece. It is located at the beginning of a staff, right after the clef, and provides essential information about the tonal center of the music. By indicating which notes are to be sharpened or flattened, the key signature informs musicians how to interpret the pitches they encounter as they read through the score.

Understanding this is crucial for performers, as it allows them to adjust their playing accordingly, ensuring that the music is performed in its intended harmony and character. The key signature does not indicate aspects such as tempo, volume, or instrumentation, which are conveyed through other markings and notation in the music. Thus, recognizing the role of the key signature is foundational to interpreting and performing a piece effectively.