2012/6/3 Federico Bruni <fedelogy@gmai...>:
> Il 03/06/2012 16:04, David Nalesnik ha scritto:
>
>> This sort of notation is very common.  Rather than notating only what is
>> physically possible for the player, the notator tries to show the
>> musical sense of the passage.

If you'd try to notate exactly what's to be heared, the readability is worse.
-> attached PNG

2012/6/3 Janek Warchoł <janek.lilypond@gmai...>:
> This is a correct engraving.

Not really.
It is physically _impossible_ to play
\relative c { \clef "G_8" <<{ e,8 [f] } \\ { e4}>> }
on a common six-string guitar. (first beat of the bar)

-Harm