Lining up notes in disparate voices

[address@hidden]

Hey all,

I'm using a trick from the LSR to print string harmonics, but I'm not getting 
the horizontal alignment I want between note columns (ideally everything should 
line up horizontally @ its center).  Any ideas on how to tweak this?

Cheers,
Mike

\relative c' {
<<
    {
      \oneVoice
      <f bes\harmonic>1
    }
    \\
    {
      \oneVoice
      \tiny
      \override Stem #'stencil = ##f
      \override Beam #'stencil = ##f
      \override Dots #'stencil = ##f
      \override ParenthesesItem #'font-size = #0
      \override NoteHead #'duration-log = 2
      <\parenthesize f''>1
    }
  >>
}