\version "2.17.97"

%%%%
%% TEXT POSITION MARKS. USE SINGLY OR IN TEXTSPANNER BOUND-DETAILS
%%%%
fifth = \markup \normal-text \roman \bold \large "V"
seventh = \markup \normal-text \roman \bold \large "VII"
ninth = \markup \normal-text \roman \bold \large "IX"
twelfth = \markup \normal-text \roman \bold \large "XII"

%%%%
%% SPANNER OVERRIDES, MAKE IT PRETTY!
%%%%
spanner = {
  \once \override TextSpanner.bound-details.left.stencil-align-dir-y = #DOWN
  \once \override TextSpanner.dash-period = #1
  \once \override TextSpanner.dash-fraction = #0.35
  \once \override Staff.TextSpanner.staff-padding = #3
}

%%%%
%% TEXT SCRIPT POSITION OVERRIDE; USE WHEN USING MARKUPS RATHER THAN
%% SPANNERS
%%%%
textPosition = \once \override Staff.TextScript.staff-padding = #3

\relative c' {
  \clef "G_8"

  % override the textScript.staff-padding, then apply markup:
  \textPosition
  g1^\fifth

  % override the spanner settings, set the spanner text and start/stop
  % the spanner:
  \spanner
  \once \override TextSpanner.bound-details.left.text = \markup \seventh
  a4\startTextSpan b c a\stopTextSpan 

  % override the textScript.staff-padding, then apply markup:
  \textPosition
  e2^\twelfth r2

  R1

  c4 d e f | g2 
  
  % override the textScript.staff-padding, then apply markup:
  \textPosition
  des2^\ninth
}