\parallelMusic incompatible with slur marker at beginning of measure?

[Ted Lemon]

I've been learning lilypond this weekend, so forgive me if this is a question 
with an obvious answer, but I am having trouble getting slurs to work with 
\parallelMusic.  If the slur marker is on the note at the beginning of the 
line, I get a fun error.   This:

\parallelMusic #'(va dynD vb) {
  % ...

  % 7
  c2 (f,4-.) d'-4-. |
  s2. s4\f |
  f4-. f'-1-. ees-. d-. |

  (ees2-- c-- |
  s1 |
  (c2-- ees-- |

  % 9
  d2.--) s4 |
  s1 |
  d2.--) s4 |
}

produces this:

aylesford.ly:47:3: error: syntax error, unexpected EVENT_IDENTIFIER
  
  (ees2-- c-- |
aylesford.ly:49:3: error: syntax error, unexpected EVENT_IDENTIFIER
  
  (c2-- ees-- |
aylesford.ly:67:3: error: errors found, ignoring music expression

The whole file is here:

https://github.com/Abhayakara/music/blob/7f9f30aa69ce08bdcf55ced7695e3621d7f9a066/aylesford.ly

If I use a phrasing slur, it works fine:

  % 7
  c2 (f,4-.) d'-4-.\( |
  s2. s4\f |
  f4-. f'-1-. ees-. d-.\( |

  ees2-- c-- |
  s1 |
  c2-- ees-- |

  % 9
  d2.--\) s4 |
  s1 |
  d2.--\) s4 |

Complete file with phrasing slurs here:

https://github.com/Abhayakara/music/blob/master/aylesford.ly

Did I do something wrong here?