Re:

[Kieren MacMillan]

Hi Petr,

> In the following example I need all the stems to be up.
>
> <<{c1} \\ {c8 f a d e d a f}>>

By putting them in the order you have, Lilypond automatically assigns  
the second part to the second (lower) voice -- instead, try

<< {c8 f a d e d a f} \\ {c1} >>

Hope this helps!
Kieren.