Re: manually set stem direction

[Jérémie Lumbroso]

nH> <{<f4 a> c8 c4 c8}\\{ s4 <f8 af> <f( af> <)g bf> <f af>}>

nH> In this case, the upper notes stem downward, and the lower notes stems
nH> upward; it's not what I want.

The voicify function already explicitly sets stem directions, try to
inverse the voices:

  <{ s4 <f8 af> <f( af> <)g bf> <f af> } \\ { <f4 a> c8 c4 c8 } >

  
If you ever need to explicitly specify directions, there are a few
property changes. The two below do exactly what they say that they do:

  \stemUp
  \stemDown

And the following lets Lilypond decide which direction to put the
stems:

  \stemBoth


This applies for several other object, for example:

  \slurUp \slurDown \slurBoth
  \phrasingSlurUp ...
  \tieUp ...


-- 
Best regards,
 Jérémie                            mailto:address@hidden