Manually connecting groups of beamed notes with a single beam

Groups of non-periodic beat structure beamed notes can be connected manually with a settable number of beams using the stemRightBeamCount and stemLeftBeamCount properties.

\version "2.24.0"

%% http://lsr.di.unimi.it/LSR/Item?id=927
% see also http://lsr.di.unimi.it/LSR/Item?id=2

%=> http://lilypond.1069038.n5.nabble.com/Beam-subdivided-at-non-periodic-intervals-td164174.html

\relative c''''{
  \time 4/4
  \key g \minor
  \ottava #1
  ees16[ 
  \set stemRightBeamCount = #1
  d
  \set stemLeftBeamCount = #1
  f ees
  \set stemRightBeamCount = #1
  d
  \set stemLeftBeamCount = #1
  c b d
  \set stemRightBeamCount = #1
  c
  \set stemLeftBeamCount = #1
  bes a g
  \set stemRightBeamCount = #1
  fis]
  \bar "!"
}