Does tempo affect use of non-harmony notes?

Question

Writing a four part piece for strings at a very slow tempo (55 bpm). On paper, it seems as though the non-chord notes I have selected should work, but I am finding some of them jarring. I am unsure if the problem is down to the slow tempo, and therefore the inevitable longer duration of the dissonances, or whether there is some other problem.

The bars concerned are the last two in the picture.

The harmony over the two bars is FM (IV 64) and F sharp dim triad, also in second inversion, as I am using C as a pedal point.

1. The first bar (FM 64), we have a passing note in the alto. This forms a 7th dissonance with the bass (2 bass parts here, both in bass clef), a sharp 4 dissonance with the tenor (alto clef), and a minor second dissonance with the soprano. Each dissonance is resolved to a consonance on the next beat (Bass octave, tenor P5 and soprano M6), but still doesn't seem quite right. Out of the two bars, this one is the least jarring, but I am still unsure about it.

2. the second bar (F sharp dim triad 64-last bar on the page) presents more of a problem. To go with the D escape note in the soprano part, I thought I would put in a B auxiliary note (highlighted) in the alto. I know that decorative notes should sound in 3rds/6ths with each other, and these form a minor third. However, perhaps down to the tempo, this seems to change the harmony to B minor for the listener, and does not sound right at all. Is this simply down to the tempo, or has a different mistake been made?

Thanks for your help!

Answer 1

Does tempo affect use of non-harmony notes?

Not tempo so much as duration. A long non-harmonic note at a fast tempo still calls attention to that note.

The problem as I see it is strongly accented dissonances that overwhelm the consonances

In particular, in measure 17, the alto B is dissonant against both the bass C and the tenor F# (perfect fourth is dissonant here). Dissonance creates a natural accent, which is further emphasized by the fact that it's also syncopated — also a source of accent — and, by virtue of being longer than the surrounding material — an agogic accent.¹

The solution I suggest is to mark the tenor in bars 16 and 17 one dynamic level lower than the other parts and add poco crescendo to the alto part.

Further discussion

1. Bar 16

Given the preceding material in bars 14 and 15, I don't find this especially jarring. However, it is important to bring out the alto part clearly.

It's easy for the chordal third (A) to get lost in the very strongly present C-F fourth (a dissonance in this context) plus the F-C fifth and C-C octave, which are very strong consonances. This relative loss of the A becomes problematic when the soprano and alto voices move, especially when they cross. The alto part must be heard clearly for the ear to follow the voice-leading properly.

2. Bar 17

Here the problem is that the F# so dominates the sound, being dissonant against the bass C, that I hear the F# as moving to B — a leap from a powerful tritone dissonance into a "double-dissonance": a major seventh against the bass C, and a perfect fourth (again a dissonance here) against the still-present F#.

Put another way, the effect is as though the alto is doubling the tenor, rather than the soprano. So I hear a leap of a fourth rather than a step of a major second.

Here again it's important to emphasize the alto line, but also to de-emphasize the tenor.

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¹ _{An agogic accent is created when one note is longer than the surrounding notes.}

Answer 2

1. In the first measure the notes (vertically are): C-C-F-A-C then B-B-F-G-C, resolving to C-C-E-G-C. This middle "passing" chord looks like G7add11/B. Coexistence of major third (B) and perfect fourth (C) is something to be used with much care. A simple solution would be to raise the soprano melody to D on the last beat of the first measure. Alternatively you can avoiding the bass going down to B. If it stays at C, or goes up to D, the issue will be avoided.

2. At the end of measure 3 soprano and alto cross. Then in measure 4 you have D13 chord (also called D7/6 in classical music, I believe). This is a beautiful chord, but I'm not sure about the voicing... the most often I see this chord voiced as D-C-F#-B. Maybe doubling seventh is not the most fortunate choice? I'm not sure.

Answer 3

On the whole, I think the treatment of dissonance in common practice is consistently the same regardless of tempo. In other words the sense of "harshness" or right/wrong isn't about how long a dissonance is help but rather it's proper handling, the preparation and resolution.

A properly handled dissonance can be held for a long time, milked for drama/expressiveness, resolved properly, and it will sound fine. Do it wrong and it sounds weird. Speeding up the tempo or shortening the dissonant note value will only disguise the problem. Perhaps it will be less noticeable, but it will probably lack an authentic common practice sound. By "proper" I basically mean handle your dissonances according to standard non-chord tone definitions you find in most harmony textbooks.

In some ways you could say slow tempos invite holding dissonances longer. If a piece is very slow with little rhythmic movement, strong dissonances can aminate the music and give it forward drive while still being slow.

The other thing worth mentioning is taking care with chromatic dissonances. Relative to the tone of resolution, dissonances above tend to be diatonic while those below can be chromatic half steps that act like temporary leading tones. You could have dissonant chromatic half steps above, but probably in some kind of "borrowed" harmony context which just reframes what is diatonic. The main point is chromatic dissonant tones can stand out as very "wrong" if they aren't handle right.