\score {
  \relative c'
    \new Staff {
      <<
        \new Voice 
        { c4 d e f 
          \textMark \markup { \box A } 
          c4 d e f 
        }
        \new Voice 
        { s4 s s s 
          \tweak direction #DOWN
          \textMark \markup { \circle 1 } 
          s4 s s s 
        }
      >>
    }
}