Do accidentals in one staff apply to notes in other staffs?

Question

For example, when reading piano music on a grand staff, I know that if there is an A# in the treble clef staff (where it's normally natural), it changes all of the A's in the rest of that measure to A#.

Do all of the As in the bass clef staff stay natural unless they also have a # symbol next to them, or are they all affected by the # in the treble clef?

EDIT: More specifically, what is the A that's circled -- natural or sharp?

Answer 1

I know this question is marked as answered, but there is some missing information.

First, the A that you have circled is definitely A♮. There is no A♯ in the key signature, and the natural sign in the treble staff is simply a cautionary accidental. The accidental is there to make sight-reading easier, not harder, since there was an A♯ in the preceding measure. The natural signs could have been placed in parentheses or omitted entirely and the meaning would not change. Both staves have A♮ in the second measure.

Second, the answer to the question in the title of your post is, "it depends." As a general rule for Western notation as it is practiced in the United States, the answer would be "no"; not only is each staff independent with respect to accidentals, each octave is independent with respect to accidentals. However, when an accidental is present in one staff but missing from another, and the accidental is not merely cautionary as in your example, a misprint is likely unless you know that such a "clash" is within the style of the piece. The same applies to an accidental missing from one octave of a staff. Within a staff, however, in some French publications, an accidental applied to one octave is intended to apply to all octaves. This phenomenon appears with some frequency in the "classical" saxophone literature. I would expect different staves still to be independent in this case, but again, misprints are possible.

Answer 2

An accidental on a note should affect all of the same note (regardless of octave) for the rest of the measure. This is the case for piano, where one performer is playing multiple clefs.

However, for an orchestral score, I would assume that each line is autonomous, whether in the same clef as another instrument or not.

As far as I am aware, the common practice is to write the accidental in each clef for the sake of clarity, even when not specifically required.

Answer 3

tpburch is correct about the grand piano staff, and that would also apply to other grand staff instruments, such as marimba.

However when in the case of clefs being for different performers, such as choral scores, orchestral scores, brass quintets, etc., each clef is treated on an individual basis.

You're looking at an a in that piano piece, and it is likely supposed to be an A#. It IS cruel of the composer/arranger/typesetter, however, since the A with the accidental is only an eighth note prior, and in the right hand. Definitely something you probably wouldn't catch the first time through; hopefully this isn't a piece anyone would be expected to sight-read!