Instruction text between header and staff

[Erika Pirnes]

I'm trying to add some instruction text in my score. I would like to position 
it between the header and the music, but I cannot seem to figure out how to do 
this, as markup cannot be placed inside a score block. I also tried taking the 
header out of the score block which still seemed to produce the exact same 
result.

(Another minor issue I had was the spacing between the title and the header. I 
wanted a bit more space in between, which I was able to obtain by adding an 
arranger field but leaving it blank. If someone has a better solution to 
suggest, I'd be happy to hear that as well.)

Here's my minimal example:

\version "2.18.2"

\header {
  title = "A Piece"
  composer = "Someone"
  arranger = " "
}

\paper {
  scoreTitleMarkup = \markup {
     \fill-line {
      \null
      \fontsize #4 \bold \fromproperty #'header:piece
      \fromproperty #'header:opus
    }
  }
}

first = \relative c''{\repeat unfold 32 {c4}}

\header {piece = "I"}

\markup {
  Here are some instructions on how you should play my piece.
}

\score {
  \new Staff {\first}
  \layout {indent = 0.0}
}


Thank you,
Erika