Strumming rhythm for chord progression

[Christian Henning]

Hi there, first post ever. I'm trying to "engrave" a strumming pattern
for a simple chord progression. I can see how a works for major chords
but I'm struggling with sus4 chords.

Here is what I have:

\version "2.12.2"
\header {
  title = " \"Creep\" by Radiohead"
}
<<
   \new ChordNames {
 \chordmode { g g:sus4  }

  }

  \new Voice \with {
    \consists Pitch_squash_engraver
  } \relative c'' {
    \improvisationOn
g1
%next line doesn't work
g1:sus4
}
>>


This is what the log tells me:

C:/Code Samples/music/songs/Radiohead/creep_1.ly:17:3: error: syntax
error, unexpected STRING
g1:
   sus4

C:/Code Samples/music/songs/Radiohead/creep_1.ly:5:0: error: errors
found, ignoring music expression

Can anyone help me out?

Thanks,
Christian