How to write chords of different durations?

[Kenneth Wolcott]

Hi;

  Another beginner question here.

  I'm still learning the basics of lLilypond engraving.

  I'm using a pre-existing piece of music as an engraving exercise
that involves piano and voice.

  When either (or both) of the piano parts have chords of the same
duration, this is fairly simple for me to understand.  However, then
either (or both) the left hand or right hand chord splits into
different durations, I am puzzled how to engrave this.

  Here is one example of what I'm trying to engrave:

the right hand of one particular measure has "bf2." and "d2 f8 bf"
(this is 3/4 time).

How to engrave this? Do I need distinct voices for this?

Thanks,
Ken Wolcott