Aligning output question

[Kevin Tough]

One of the last hurdles I have to figure out to start producing course
notes is to Left/Right jusify staff output, if it is possible. I've done
some document scanning and not found my solution. Would anyone be able
to point me in the right direction or check my input code to see if it
even has the right structure. Here it is...

\version "2.16.2"

% BasicNoteTabTemplate.ly

\language "english"

\header {
  %title = "First String Practice"
  %composer = "Composer"
  %subtitle = "English with Guitar"
}

song = {
  e1 f g e f g e f g f e \bar "|."
}

<<
  \new Staff \relative c'' {
    \numericTimeSignature \time 4/4
    \song
  }

  \new TabStaff \relative c' {
    %\override Stem #'transparent = ##t
    %\override Beam #'transparent = ##t
    \song
  }
>>

<<
  \new Staff \relative c'' {
    \numericTimeSignature \time 4/4
    e2 e f f g g e e f f g g e e f f g g f f e e \bar "|."
  }

  \new TabStaff \relative c' {
    %\override Stem #'transparent = ##t
    %\override Beam #'transparent = ##t
    e2 e f f g g e e f f g g e e f f g g f f e e \bar "|."
  }
>>

Another guestion is about variable usage. Can variables be changed or
are they equivalent to constants? 

Namaste,

Kevin Tough