[css3-speech] voice-pitch

http://dev.w3.org/csswg/css3-speech/#voice-pitch

   # voice-pitch: <frequency> | <percentage> | <relative-value> && relative
   ...
   # <frequency>
   #   Specifies the average pitch of the speaking voice using an
   #   absolute value in frequency units (Hertz and kiloHertz, e.g.
   #   "100Hz", "+2kHz") as per the syntax of frequency values
   #   defined in [CSS3VAL]. Only positive values are allowed.
   ...
   # <relative-value>
   #   Specifies a relative change (decrement or increment) to the
   #   inherited value. The syntax of allowed values is a <number>,
   #   followed immediately by either of "Hz" (for Hertz) or "kHz"
   #   (for kiloHertz) or "st" (for semitones).
   # relative
   #   This keyword specifies that the provided value is expressed
   #   relatively to another base value. This is in order to
   #   disambiguate from absolute <frequency> values.

I think, given that semitones can only be relative, that it would
make more sense to define this as either
   | voice-pitch: <frequency> && relative? | <percentage> | <semitone>
or
   | voice-pitch: <frequency> && absolute? | <percentage> | <semitone>
depending on whether
   voice-family: 120Hz;
   voice-family: 5Hz relative;
or
   voice-family: 120Hz absolute;
   voice-family: 5Hz;
seems the more reasonable pair.

~fantasai