This looks almost right. It's from Chopin Nocturne Op9 no 3 :
\version "2.16.0"
\relative c'
{ \clef treble
\time 6/8
\key b \major
ais'4 gis8 << {\hideNotes gis'4.~\>\(
gis16 fis eis dis cisis dis\! e eis\) gisis,\( ais \times 2/3
%%\override TupletNumber #'stencil = ##f
{\unHideNotes b16\accent[ s ais]}
\hideNotes \stemDown s4. fis4\) fis16 eis} \\ {gis'4.
gis16 fis eis dis cisis dis e eis gisis, ais \times 2/3 {b16 eis, ais}
\unHideNotes \stemUp gis4.\accent fis4}>>
}
The slur starting on the g# is much too high. I can see why this is by un-hiding the upper voice notes. But is there a way to bring that slur line down? I also wonder if my approach is correct at all. Does it make sense to treat those two bar-up sixteenth notes as a separate voice?
Also, I don't want to see the "3" both over and under the triplet. But look at what happens if I use the \override
that appears in the comment. It removes the number "3" but also miscalculates the notes within the triplet.
--John K