Re: cross-staff stems in a piano part

[Simon Albrecht]

On 12.12.2017 01:12, Chris Jones wrote:
> One example I looked at when I got started on this used double "<<  >>"
> brackets to represent chords whereas the official lilypond documentation
> recommends using single "<  >" brackets.
>
> How are they different in terms of lilypond's behaviour?

The official LilyPond documentation tends to be correct, especially if 
you’re looking at the version corresponding to the program version 
you’re using.
Chords are entered using <>. <<>> are used to wrap ‘simultaneous music’, 
i.e. any number of music expressions that are going to be inserted in 
parallel – whether it’s within one voice, multiple voices in a staff or 
multiple staves/staff groups/… in a score.

This is such a fundamental concept that I have to say: you really should 
work yourself through the Learning Manual from beginning to end. One 
difference between LilyPond and other notation software with GUI is that 
it’s unfortunately a really bad idea to learn it by trial and error. 
There are several such fundamental concepts which you should get a grip 
on to save yourself lots of grey hair.
The Learning Manual also explains how to use the other documentation 
resources.

Best, Simon