Re: Em2 chord

[Michael Watts]

>>We also use add9, add11, and occasionally add#4 and others. Are "add" 
chords supported in Lilypond?

Sure.
\version "2.10.33"

test = \chordmode { c1:3.5.9 c:3.5.11 c:7.11+ } % to use your example

\score {
   <<
  \new ChordNames \test
  \new Staff \test
   >>
   \layout { ragged-right = ##t }
}