\version "2.12"

X = \once \override NoteHead #'X-extent = #'(0 . 1.3)

%                Takt 1                          Takt 2

<< { \normalsize f'2     \teeny      f'4 f'4     f'2 f'4 f'8 f'8 }
\set Staff.instrumentName = "Unsinn"
\\ {      \teeny f'4 f'4 \normalsize f'2         f'2 f'4 f'8 f'8 }
>>

<< { \normalsize f'2                 f'2         f'2 f'4 f'8 f'8 }
\set Staff.instrumentName = "Sinn (1)"
\\ {   \teeny \X f'4 f'4 \X f'4 f'4  \normalsize s1 }
>>

<< { \normalsize f'2                 f'4 f'4     f'2 f'4 f'8 f'8 }
\set Staff.instrumentName = "Sinn (2)"
\\ {   \teeny \X f'4 f'4 \X f'2      \normalsize s1 }
>>