Will the accidental of a mordent affect another mordent that is in the same measure?

Question

The first mordent in this measure will be played as D , C# , D. The second mordent in the same measure doesn't have a sharp like the first mordent.

Will the sharp accidental of the first mordent affect the second mordent since they are both in the same measure?

There is a very similar question (Would an accidental in a mordant still be effective for the whole measure?); however, the question itself is not specific to this situation, and although the primary answer addresses it, it's ambiguous.

I'm looking for a documented answer to this specific case.

Answer 1

This scenario is undefined and therefore ambiguous. It should be considered an editorial error.

From Elaine Gould's Behind Bars:

Accidentals affecting ornaments

An altered pitch should be confirmed or cancelled for an ornament later in the bar....

An accidental indicated for an ornament should be confirmed or cancelled when the pitch is reiterated later in the bar as a measured note. (p. 84)

Thus, the example given in the question should be written either as

and both played D-C#-D, or

with the first played D-C#-D and the second played D-Cnatural-D.

In the ambiguous situation, the only recourse would be:

1. look to original sources;
2. look to recorded evidence;
3. make a decision based on musical analysis.