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.
The easiest grip here is xx5452 — no barre. None of the shapes for Emadd9 uses an open string, so every one of them is movable; the lowest sits at the 2nd fret. 3 of the 10 need a barre. Together they cover the neck from the 2nd fret to the 14th.
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.