Finding Roman Numeral Degree of Measure with Accidentals

Question

I'm working on a Roman numeral analysis of the Minuet in G Minor by Petzold. The piece is in the key of G minor. In measure 12, there is an accidental which changes the B flat to a B natural. I've determined a chord that matches the music, by sound, but I'm not sure how to label the triad. Do I label it as a triad in a different key or do I skip labeling it? The triad in question is a B natural, D, F triad. I've attached an image of the sheet in question below. Thanks,

EDIT: Sorry I didn't mention it and my original question, but you were all very attentive in pointing out that I did it in the wrong key. I am working on redoing my work so far... Thank you for all your answers!

Answer 1

(As Dekkadeci said, your analysis is actually in Bf major, instead of G minor, so you'll have to adjust your Roman numerals!)

To the actual answer, though: keep in mind that Roman-numeral analysis strives to show the function of each chord. As such, whenever you encounter a chromatic chord, you want to explain how this chord is functioning.

In most cases, a chromatic chord will be a major triad (or a major-minor seventh chord) where you don't expect it. Often these chords will resolve down a perfect fifth, showing that they are functioning as a dominant of the succeeding chord.

In your example, the Bn creates a G7 chord, and that major-minor seventh chord quality really lends it a dominant flavor. Assuming it resolves to C, this G7 is thus functioning as the dominant of C. We can then do a little "algebra":

 G7/C
 V7/C (because G is V of C)
 V7/iv (because C is iv in G minor)

Giving this chord the label of V7/iv. (I note that you don't use inversions in your analysis, but it will be a V65/iv if you consider the Bn as the bass pitch.)

As a final test: How would you label the chord A C# E in G minor?

Answer 2

My answer assumes that, instead of assuming your analysis is in B flat major (your use of vi to label the first chord gives that away), your analysis is in G minor (so vi is changed to i, I is changed to III, you likely should insert an extra chord in Bar 7 where the F# is so you can more easily explain how the last chord there is i, etc.).

For the last chord in Bar 12 alone (the one with the B natural), I'd call that vii°/iv, as it tonicizes C minor (the subdominant of G minor).

Answer 3

It looks like your analysis was done "by eye" only, not "by ear" (which in the end, is the only thing that matters about music). If you can't "hear" a simple piece like this by reading the score (i.e. not by actually playing it), that is a gap in your musical training that needs to be filled!

All your roman numerals are wrong, because (even if you analysed "by eye") you ignored the title of the piece, which says "G minor" - unless you assume Petzold made a mistake in the title, of course.

Considering the harmonic cadences of each phrase, your B flat chord in bar 4 doesn't make much sense in G minor, compared with a D (major or minor) chord. That would then suggest that the B flat in bar 4 is simply an (accented) passing note, and by analogy, the B natural in bar 12 is another one.

Your analysis of bars 5-7 doesn't look right either - though you did get bar 8 right, though you might not have noticed the similarity between bars 8, 4, and 12. But I'm not going to do the whole of the analysis for you!