\version "2.18.2"

beam-stem-height =
#(define-music-function (parser location start-in length-in)(number? number?)
  "Takes a list containing values for:
  - the stem-start in Y-direction
  - the stem-length
  Values can be positive or negative, depending on direction
  but may produce a warning if only one value is negative:
    'warning: weird stem size, check for narrow beams'
  "
  #{
    \override Stem.direction = #(if (positive? length-in) UP DOWN)
    \override Stem.stem-begin-position = #start-in
    \override Stem.length = #(abs length-in)
    \override Beam.after-line-breaking =
    #(lambda (grob)
      (let
        ( (stems (ly:grob-array->list (ly:grob-object grob 'stems)))
          (position (if (positive? length-in)
              (/ (+ start-in (- (abs length-in)
                (ly:grob-property grob 'beam-thickness))) 2)
              (/ (- start-in (- (abs length-in)
                (ly:grob-property grob 'beam-thickness))) 2)
            )
          )
        )
        (ly:grob-set-property! grob 'positions (cons position position))
        (for-each
          (lambda (stem)
            (ly:stem::calc-stem-begin-position stem)
            (ly:grob-set-property! stem 'length (abs length-in))
            (ly:grob-set-property! stem 'stem-begin-position start-in)
          )
        stems
        )
      )
    )
#})

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% EXAMPLES
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

{
  \beam-stem-height #5 #7
  c''8[ d'']
  c''16[ d'']
  c''32[ d'']
  \autoBeamOff
  c''8 d''16 e''32
  \beam-stem-height #-7 #-10
  c''8[ d'']
  c''16[ d'']
  c''32[ d'']
  \autoBeamOff
  c''8 d''16 e''32
}

\new TabStaff \with {
  stringTunings = #ukulele-tuning
  \tabFullNotation
  \beam-stem-height #-5 #-5
} {
  \relative c' {
    r8 g'\4 c,4 e2 |
    a1 |
    g8\4 c, e a c,[ c] a'8 a |
    \beam-stem-height #5 #5
    r8 g\4 c,4 e2
    a1
    g8\4 c, e a c,[ c] a'8 a
  }
}