piano staves and lyrics

[Gerard McConnell]

Hello,

I've included a minimal example below; why doesn't it work and how do I correct it?
(It works fine without the alto and tenor parts.)
Many thanks yet again,
Gerard

\version "2.12.2"

\score {
   \new PianoStaff {
      <<
      \new Staff {
       <<
       \new Voice="soprano" { \voiceOne
        \time 2/2
        \key d \major
        \relative c' {   fis2 e    }
        }
       \new Voice="alto" { \voiceTwo
        \relative c' {  d2 d4( cis)  }
       }
     >>     
      }
    
   \addlyrics { please help }
% \lyricsto soprano { please help } also fails
    
  \new Staff {
       \clef bass
       <<
       \new Voice="tenor" { \voiceOne
        \time 2/2
        \key d \major
        \relative c' {  a2 g  }
       }
       \new Voice="bass" { \voiceTwo
        \relative c {  d2 ais  }
       }
             >>
      }
      >>
   }
}