Question: I wanted to highlight a particular chord of my [previous question](https://music.stackexchange.com/q/114106/77758) because it was bugging me a bit. What would you call a dominant triad over a subdominant bass, in pop/jazz roman numeral analysis? It could be seen as a `V7` in third inversion, but if you have a strong subdominant bass it doesn't really sound like it. But just calling it a `IV` seems... meh. Especially because we call the inverse, a subdominant triad over a dominant bass, a sus chord.

**Update**: Thanks all for your responses. As most of you have said, roman numeral analysis isn’t really suited for these kinds of chords. I might decide to just slash chords for bass and then come up with a different way to notate secondary chords and modulations in a functional manner. I don’t want to do this literally because that doesn’t make sense in a tonic-agnostic notation.

[![Sample](https://i.stack.imgur.com/MbtNF.png)](https://i.stack.imgur.com/MbtNF.png)

Answer: 
It's triads over a pedal. F, G/F, F. If tempted to call the second chord G7/F, take the idea a little further...

[![enter image description here](https://i.stack.imgur.com/HSiwn.png)](https://i.stack.imgur.com/HSiwn.png)

Wouldn't it be ridiculous to call that new chord A♭6/F? No, these are plain triads over a pedal and deserve to be named as such.

But I don't think Roman numbers deal with this very well. It likes everything to be functional.

(This, of course, would be a different matter. Here it IS a last-inversion G7.)
[![enter image description here](https://i.stack.imgur.com/cZGPU.png)](https://i.stack.imgur.com/cZGPU.png)
I agree that these are modal 'color' chords over a pedal point. The V chord is not functioning as a dominant at all; rather, it brings out the Lydian nature of the IV chord. The Lydian mode gives that faraway, otherworldly sound, and is especially exploited in cinematic music.

You might have better luck with pop/jazz music notation, even though you lose the tonic-agnostic benefit of roman numerals. Check out this excerpt from a jazz lead sheet:

[![Jazz lead sheet excerpt](https://i.stack.imgur.com/V2ZI9.png)](https://i.stack.imgur.com/V2ZI9.png)

Here we see chords progressing over pedal tones. The emphasis is on readability. Functional analysis is left open to debate - this kind of music can have multiple, overlapping harmonic interpretations.