\version "2.11.62"
\include "italiano.ly"

\header {
 title = "Tremolo"
}

tremoloA = \relative sib
{ % this works properly
		\times 2/3 {\repeat tremolo 6 {<sib sol' sib>8} } 
		\times 2/3 {\repeat tremolo 3 {<sib sol' sib>8} } 
		\times 2/3 {\repeat tremolo 3 {<sib mi sol>8} }
}
tremoloB = \relative sib
{ % this is in musical terms identical, but brings up wrong results
		\times 2/3 {\repeat tremolo 9 {<sib sol' sib>8} } 
		\times 2/3 {\repeat tremolo 3 {<sib mi sol>8} }
}
expected = \relative sib
{ % this, but with tremolo bars
		<sib sol' sib>2. 
		<sib mi sol>4
}
countHelper = \relative sib
{
		\repeat unfold 35 {\times 2/3{r16}}			% helps counting the beats for tremolo 9
}

\score 
{
  \new PianoStaff
  <<
    \new Staff 
	<<
		\tremoloA	
	>>
    \new Staff  
	<<
		\tremoloB
	>>
    \new Staff  
	<<
		\expected
	>>
    \new Staff  
	<<
		\countHelper
	>>
  >>
}