I'm writing chords for a pop piano part (so definitely want to follow what is more intuitive for pop/jazz players rather than sticking hard to the music theory books). The chord in the right hand is a Dm7 and it is over Eb in the bass. Generally, would it be preferable to see this as Dm7(b9)/Eb or Dm7/Eb?
Dm7/E♭ would be preferable. On the basis that were there a bass player or the bass (slash) note could be played on a different instrument, a guitarist, for example, could simply play Dm7.
Dm7(♭9)/E♭ may also have a different connotation. That E♭ wouldn't necessarily be regarded as the lowest note (as indicated by the slash), but as an extension to the chord - a ♭9 - on top rather than underneath.
Dm7/Eb is sufficient in this case. It is better than Dm7b9/Eb, because it better suggests the voicing – normally b9 should be above the root, in a higher octave.
Interesting chord... I wonder, is it a passing chord, or a chord where Dm7 is static and the bass line is moving? Slash notation is definitely appropriate in such situation, as it signalizes a specific voicing.
Context is all. But I’d hazard a pretty confident guess that the E♭ isn’t part of the upper structure but purely the bass note. ( Maybe the tonic or dominant? Is there a string of chords all over an E♭ bass note?) So write Dm7/E♭.
Slightly different situation - remember that favourite wedding song ‘Feelings"? Em, Em/ D♯, Em/D etc. I’ve seen song copies that find some torturous way to spell the second chord as D♯ something-or-other. No!
As others have commented, first, probably readibility suggests Dm7/Eb.
It might depend whether that Eb is some sort of ostinato... so that the Dm7 is a "passing" harmony, ... or perhaps the Eb is a passing tone, within a key where Dm7 is a typical harmony. Even so, either way, if I were reading something cold, I'd prefer Dm7/Eb (or, conceivably, ii7/...).
I'm pretty sure the actual chord isn't Dm7b9.
The way I see it: there are two kinds of slash chords:
- Chord inversions: here the actual (full) chord is written before the slash, and an alternative bass note is written after the slash. That alternative bass note doesn't change what chord it is, just makes it an inversion of that chord. E.g.
C7 / Emeans you want the 3rd in the bass instead of the root.
- Alternative notations: here the actual root of the chord is written after the slash, and a chord to play above that root is written before the slash. This way it's just an alternative notation. E.g.
E / Ccould be an alternative notation for
CMaj7+. It may also indicate a particular voicing (where the right hand plays the E triad, possibly inverted, instead of spreading out the notes).
In your case, it depends on the context, but intuitively I'd guess that this is actually an inversion of a F dominant chord, with the 7th (
Eb) in the bass and the 13th (
D) added. If that's the case, I'd write it as
F13 / Eb.