# What are idiomatic ways to harmonize ^5 ^4 ^3?

I have only learned a few chords in my harmony and voice leading book. I, I6, V, V6, ii, ii6, IV and the inversions of V7. I am now trying to harmonize this melody and so far the most idiomatic bassline to use for this descending line according to my book is a a pattern of 10ths between bass and soprano. So in this case it would be I6,V43,I with 5^4^3 in the soprano. However, in this case it wont work because the ^6 before the descending line is a subdominant harmony and would need to go to a dominant chord. My bassline for the ^5^4^3 doesnt really work I think. That said would my only other option be V, V7 ,I?

• Are you required to match the rhythm of the melody and harmonize every single note independently without passing tones? Also. . . what's the next note in the melody? Is it to the A? If so, I might do half-notes: A-B-D-C#. Sep 15, 2021 at 20:55
• Correct. Every note needs to be harmonized. Next note is A
– user35708
Sep 16, 2021 at 6:43
• Okay in that case, I'd probably go UP to D rather than down, and then just step down the scale with the melody in 10ths, finishing up-E, down-E, up-A Sep 16, 2021 at 9:15
• Are you not allowed to use repeated or held notes in the bass when harmonizing? I'd personally use only E for the bass under ^5 ^4 to go with V-V7. Sep 16, 2021 at 11:52

### TL;DR

Idiomatically, the best options in this specific instance are:

1. The given solution
2. Parallel 10ths
3. Voice exchange

### Parallel 10ths

I mention this first only to reiterate what's already written in the OP. Parallel 3rds, 6ths, and 10ths are highly idiomatic, so that's always a good place to start when considering a harmonization. See below for why it's a very good solution in this particular case.

### Contrary motion / voice exchange

Another highly idiomatic option is to counter the soprano 5-4-3 with 3-4-5. This is called "voice exchange", because the soprano and bass (in this case) swap scale degrees 3 and 5. Harmonically this would generally be I6-IV-I64 or, less commonly, I6-ii6-iii.

Voice exchange is just a special case of contrary motion. Once could just as well accompany 5-4-3 with 1-2-3, and harmonizing with I-V43-I6.

### Regarding IV proceeding to V

This is not the only option for IV. IV (and, less commonly, ii) can also be used to prolong a I chord. I-IV-I is a perfectly acceptable progression.

This means that parallel tenths will work very well for the harmonization of the melody given in the OP.

• Another option is to harmonize ^4 with ^3 in the bass, which is a bit difficult to analyze harmonically, then harmonize ^3 with ^4 in the bass, which more straightforwardly yields IV7. This is not what we tend to think of as idiomatic, and I first encountered it in the music of Aaron Copland, but the second place I encountered it was in the music of J. S. Bach. It doesn't work if you're cadencing on ^3, but that's not the case in the example given in this question. Sep 15, 2021 at 22:28
• @phoog Big bonus points if you can find the Bach reference! Sep 15, 2021 at 22:32
• Aaron My textbook says thay intermediate chords move to dominant chords not to tonic chords. Later in the book (because I skip ahead from time to time) it does discuss IV going back to I but the level that I am on only allows intermediate Harmony to move to dominant Harmony. Having said that, the IV chord on beat 2 cannot move to I or I6 right? Also, your I6 ii6 iii harmony involves bass notes 3-4-3 not 3-4-5. Please let me know if this is right?
– user35708
Sep 16, 2021 at 6:51
• Can you please explain your proposed solution of parallel tenths using I IV I for 5-4-3?
– user35708
Sep 16, 2021 at 7:08
• @armani I-IV-I6-V43-I Sep 16, 2021 at 7:49