This Em9 chord features a semitone interval, with the F# on the fourth string ringing boldly against the G of the open third ... It is not a ‘sus4’ chord, because the 3rd is present.

It could also correctly be called a C/G chord, but the context I’m imagining it in is resolving to a G major by removing the E (6th) and C (sus4) on the fourth and second strings. The fifth stri ...