Slant of beams

[Helge Kruse]

Hello,

I have an excerpt of my score, that doesn't look nice. The beams are
horizontal in the first measure and I don't know why. The stem's length of D
and C is much too small. To avoid a collision the slur has been blown up and
looks like, ... "blown up".

How can I change the beam's slope (or whatever the correct English word is
;-)?

Regards,
Helge 


\version "2.7.39"
\include "deutsch.ly"
        
     upper = \relative c' {
                \clef treble
        \key b \major
        \time 6/8
                c16 es fis es d a c es fis es d a |
                c16 es a ( g fis es d c
                        \change Staff = "lower" b a g fis |
                        es8 ) \change Staff = "upper"
                        r8 r8 r4 d'8  |
         }
     
     lower = \relative c {
        \clef bass
        \key b \major
        \time 6/8
                d2.~ |
                d4. r4 r8 |
                s8 <d d,>8 <cis cis,> <c c,> <b b,> <a a,> |
                    }
     
\book {
     \score  {
        \context PianoStaff <<
           \set PianoStaff.instrument = "HARPE  "
           \context Staff = upper \upper
           \context Staff = lower \lower
        >>
        \layout { }
     }
}