The standard grips this chord is usually shown with.
Emadd9 is E, G, B and F# — Em with the ninth added, and no seventh.
It sounds sharp-edged. The ninth grinding a whole step under the minor third is the edge an m9 softens.
Minor tonic — a triad with one colour on it.

| E | G | B | F# |
|---|---|---|---|
| 1 | ♭3 | 5 | 9 |
Also written Em(add9), Emin(add9) or E-add9. The same chord either way; which spelling you meet depends on who wrote the chart.
Emadd9 in 1st inversion puts G in the bass instead of E, the 3rd of the chord. The notes are the same; what changes is what the bass line does, which is most of why you would reach for it — it lets the lowest voice move by step where the root would have jumped.
2 of Emadd9’s 10 common shapes do this:xx5452x-10-9-9-7-x
All 10 common shapes as fret numbers, lowest string first. Hover or tap one to see it drawn.
How you get to it. The turn that lands on Emadd9 is F#m7♭5 to B7♭9: the ii and the V of E minor, which is where a minor tonic is usually arrived at rather than simply begun on.
In which keys. Every note of Emadd9 belongs to D major (the ii, the supertonic), E minor (the i, the tonic), G major (the vi, the submediant) and B minor (the iv, the subdominant).
Every note of Emadd9 is in E dorian, E natural minor, E harmonic minor and E melodic minor.
Change one note of Emadd9 and you have Em (drop the ninth), Esus2 (drop the minor third), Esus2sus4 (the minor third becomes the fourth), Em6 (the ninth becomes the sixth), Em69 (add the sixth) or Em7 (the ninth becomes the flat seventh).
Emadd9 is a minor chord — root, minor third, fifth. Minor chords on every root.
The common shapes and the derived voicings come from different places, and both are explained in how this site is built.
Shows each chord the way this style would voice it, and marks which of its alternatives belong to the idiom.