\version "2.16.0"

% cue function that typesets associated lyrics
cueDuringWithLyrics =
#(let ((stafftag 'Staff)
       (cuenr 0))
   ; cue voice counter, if there are multiple simultaneous quotes
   (define (cue-id) (set! cuenr (+ 1 cuenr)) (format "cue~A" cuenr))
   ; get context property for alignment
   (define (alignlyrics direction)(if (eq? UP direction) 'alignAboveContext 'alignBelowContext))
   ; the music function
   (define-music-function (parser location quote direction lyrics music)
     (string? integer? ly:music? ly:music?)
     ; we need the staff-id of the contained cueVoice
     ; and we need a cue-id
     (let ((staffid #f)
           (cueid (cue-id)))
       ; dummy engraver to get the parental staff-id
       (define (getstaffid context)
         (let ((staff (ly:context-find context stafftag)))
           (if (ly:context? staff) (set! staffid (ly:context-id staff)))
           ; this engraver does nothing
           (list)))
       ; engraver to set the lyric alignment
       (define (aligncue context)
         `((initialize .
             ,(lambda (trans)
                ; if we have a staff-id ...
                (if (string? staffid)
                    ; ... set the alignment property
                    (ly:context-set-property! context (alignlyrics direction) staffid)
                    ))
             )))
       ; now create the music
       #{
         <<
           % the music voiceOne/Two for UP/DOWN resp.
           { $(if (eq? direction UP) #{ \voiceTwo #} #{ \voiceOne #}) $music }
           \new CueVoice = $cueid \with {
             % create CueVoice with staff-id grabbing engraver
             \consists #getstaffid
           } {
             % the cued music voiceOne/Two for UP/DOWN resp.
             $(if (eq? direction UP) #{ \voiceOne #} #{ \voiceTwo #})
             % the cue is quoted, use a skip event ... the music is in the main part
             \quoteDuring $quote { $(skip-of-length music) }
           }
           % create the lyrics with smaller text-size
           \new Lyrics \with {
             % the alignment setter fetches the grabbed staff-id
             \consists #aligncue
             fontSize = -2
             \override LyricText #'font-shape = #'italic
           } % lyricsto the CueVoice
           \lyricsto $cueid \lyricmode { $lyrics }
         >>
         % reset voice to oneVoice
         \oneVoice
       #}
       )))

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%% Example

% create quote
\addQuote "myquote" \relative c'' {
  \repeat unfold 10 { bes4 a c b }
}

% make music ...
<<
  % staff with a unique context-id
  \new Staff = "mystaff1" {
    R1
    % cue with lyrics: one syllable less than needed
    \cueDuringWithLyrics "myquote" #DOWN \lyricmode { b a c h x y z } { R1*2 }
    % more music
    \relative c'' \repeat unfold 4 { c4 a f d }
  }
  \new Staff = "mystaff2" {
    R1
    % cue with lyrics: more syllables than needed
    \cueDuringWithLyrics "myquote" #UP \lyricmode { b a c h x y z q q q } { R1*2 }
    % the following notes are shifted, if the last cue-note has a syllable?
    \relative c'' \repeat unfold 4 { c4 a f d }
  }
>>