voices

[Hans Kieserman]

Hi-
Why does Lilypond try to "join" voices?  Sorry I don't have a better way 
to explain it- but, for example, a quarter-note/crotchet in one voice 
that occurs at the beginning of a run of eighth-notes/quavers will 
apparently cause the first quaver to become a crotchet, which doesn't 
seem to make much sense.

I think of the Voice context as independent lines of counterpoint; is 
that incorrect?

Thanks,
Hans

ex.
\score {
\notes <
\context Voice {
        c''4 c''4 c''4 c''4
}
\context Voice {
e''8 e''8 e''8 e''8 e''8 e''8 e''8 e''8
}
>
\paper {}
}