percussion (drum set) help

[Paul Scott]

How can I move the eighth rest to the level of the snare drum part?
sn8\rest doesn't seem to be allowed.
Any other feedback on my code would also be appreciated.
I'm successful with most of my percussion code.

\version "2.19.80"

\score{
  \new DrumStaff
  \drummode{
    \clef percussion << { cymr4 4 4 4 } \\ { r8 sn8 4 4 4 } { hhp4 4 4 4 } >>
  }
}

TIA,

Paul