\version "2.17.6"

\header {
  texidoc = "An episema can be typeset over a single neume or a
melisma.  Its position is quantized between staff lines."
}

#(set-global-staff-size 26)
\include "gregorian.ly"

\new VaticanaVoice {
  \revert Score.SpacingSpanner.packed-spacing
  a\episemInitium\episemFinis
  \[ a\episemInitium \pes b \flexa a\episemFinis \]
  \[ a\episemInitium \pes b \flexa a b\episemFinis \flexa a \]
}