Sponsored feature request--partially-tied chords

[Steve D]

Trevor Baca recently asked how one might write in LilyPond tied chords in
which only *some* (one or more, but not all) notes are tied to the
following identical chord.

I am also interested in this, because it sometimes happens in piano
music, and I would be interested in sponsoring a feature in LilyPond 
which one could use to prevent one or more notes within a chord from
being tied.

For example, consider a C 7 chord tied to
another C 7:

<c e g bes>4~ <c e g bes>

In piano music (and perhaps other polyphonic instruments) a chord can be
played in such a way that some notes are sustained (tied) and some are
sounded or repeated. Someone might notate a piece in which the c and
b-flat of the above chord are held, while the e and g are struck in the
second and subsequent identical chords. It might be nice to be able to
write something like:

<c e\noTie g\noTie bes>4~ <c e g bes>

At any rate, if Han-Wen thinks this is worthy of some thought and
effort, I would be happy to sponsor such a user-specified "selective
exclusion of notes" or partially tied chord feature.

Steve Doonan
New Mexico US
-- 
----------------------------------------------------------------
Nearly all men can stand adversity, but if you want to test a
man's character, give him power. -Abraham Lincoln 
----------------------------------------------------------------