The \\ construct for simultaneous voices

[Trevor Daniels]

I've finally got around to thinking about the introduction to 
parallel voices in the Learning Manual - currently sections 3.2.1 
and 3.2.2.  You'll remember the many discussions about the two 
constructs - explicit voices and the \\ construct, and the
final agreement to introduce explicit voices first, reversing the 
present order.  I'm now minded to remove mention of the \\ construct 
from the LM altogether, except for a brief reference to the topic in 
the NR.  This seems the simplest way of avoiding the confusion that 
frequently arises with the current approach.

Before I start merging 3.2.1 and 3.2.2 to do this I'd welcome your 
comments.

Trevor