Vertically centering a song text.

[Robert Blackstone]

Dear List,

Could anybody help me (a newby) with the following issue:

I am setting a song, vocal line and keyboard, with two sections, the first of which has two verses, the second only one, as in the ME, copied, and slightly modified, from http://www.lilypond.org/doc/v2.18/Documentation/notation/techniques-specific-to-lyrics  

%%%%%%%%%%%%%%%%%%%%%%%%%%%\score {

  <<

    \new Staff {

      \new Voice = "melody" {

        \relative {

       

          \repeat volta 2 { b'4 b b b }

           \repeat volta 2 {a4 a a a }

        }

      }

    }

    \new Lyrics \lyricsto "melody" {

     <<

{ The first time words. }

\new Lyrics {

 \set associatedVoice = "melody"

 Sec -- ond time words.

}

      >>

      O- ther Ly- rics.

    }

  >>

}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

How can I shift the lyrics of the second part vertically so that it is centered with respect to the first part, instead of  being in line with "The first time words".

Thanks in advance.

Best regards,

Robert Blackstone