# Accidentals in the same register in a measure with a clef change

From a notational perspective, is it clear that the second C4 in the image below is flat (if in fact it is)? I've never encountered a situation like this before.

Yes, it's C♭.

The standard definition of an accidental is that, assuming only one voice in a staff, the accidental modifies the specified pitch in that register and in that register only.

In other words, the C4 at the end of beat 3 is already lowered on account of the C♭4 on beat 2 of the left hand. The clef change makes absolutely no difference, because the C in that register has already been lowered to C♭4.

• Do you know if this is strictly true across staves (in piano music)? For example, suppose the same C4 had been notated in the upper staff; would it also be flat? Mar 25, 2018 at 4:34
• Good question. My guess would be no, since typically each staff is thought of as a separate hand, and thus a separate voice. But I don't have a source for that; maybe someone has a quote from Gould's book they'd be willing to share. Mar 25, 2018 at 4:38
• I think new accidentals are required once you change staves. An easy example where this has to be necessary is passages where the same 16th-note chord is repeated in alternate hands (a la the Prokofiev Toccata), and alternate staves. Without accidentals in both staves, you wouldn't be sure whether you should be repeating the same note, or executing more of a trilled figure. Mar 25, 2018 at 4:46
• Harmonically, it is a Cb, but I don't believe it is all that clear in the score. When reading quickly, we don't look back at the other clef and say "oh, yes, this C is the same register as that C and so it is flat." Our hands and ears may assume that Cb, but they aren't told that by the written score. Apr 6, 2018 at 15:50

First, harmonically, it is most reasonably flat, so if that is the only thing stumping you, be pretty well assured that it is flat. Second, notationally, as it stands, with no other harmonic context, I think you could find it argued either way. There is, in the left hand, a preceding C-flat, so regardless of clef, your hand has already played the note there, and the author or arranger may assume the performer will understand that the flat persists. Otherwise, to be unequivocally clear, he could've added a courtesy accidental. I believe you are well in the clear to read that as C-flat.

• I'm downvoting because the OP is already aware a flat is implied, but he is specifically asking if it is notationally indicated, and this answer is entirely speculative regarding notational rules. Mar 25, 2018 at 4:52
• Richard's answer is correct. (This example could not be argued either way). An accidental within a staff modifies that pitch at that register for the remainder of the measure. A clef change may make it more difficult to see that the notes are the same at a glance, but does not change the rule. Mar 25, 2018 at 4:54
• I would have added a courtesy accidental here myself, since the middle C was flatted in the bass clef and this is in the treble. Mar 25, 2018 at 6:03
• @Gooseberry . Did you not see the OP's statement "if in fact it is"?
– Neal
Mar 25, 2018 at 12:07
• @Ben I . What of chorale music, such as what you might find in a hymnal? Soprano and Alto on one staff, Alto sings accidental, but don't notate accidental for the repeated note for the other voice, just because it's the same register?
– Neal
Mar 25, 2018 at 12:10