Feature request: some convenient new grobs

[Mark Polesky]

Hi everyone,

First of all, I'd like to thank all of you for your hard
work -- LilyPond is getting better and better!

So, I'm getting tired of abusing the TextScript,
RehearsalMark, and TextSpanner grobs to do things like
"rit." and "D.C.", because things usually get really messy
with tweaks and overrides, and conflicts between
simultaneous marks, spanners, etc.

Thanks to Harm's suggestion, I recently tinkered with this
nice snippet for getting simultaneous RehearsalMarks...
http://lists.gnu.org/archive/html/lilypond-user/2011-08/msg00157.html
...but even that solution has its limitations, and I'm 
struck thinking there must be an easier way for the user.

Maybe I'm in the minority here, but here's what I'd like to
see (I haven't put much thought into these grob/command
names, it's just the idea):


TempoMark => \tempoMark  (instead of \tempo?)
  keep this as is, for primary tempo indications like
  "Allegro", and metronome markings


SubTempoMark  => \subTempoMark
  for things like "accel.", "rit.", "a tempo", etc.,
  default could be: 
    left-aligned on the musical moment, medium-italic


SubTempoSpanner => \startSubTempoSpanner, \stopSubTempoSpanner
  for things like "rit. - - -", etc.


RehearsalMark => \rehearsalMark (instead of \mark?)
  keep it as is, for rehearsal letters or numbers that are 
  usually centered over the barline.


RoadmapMark   => \roadmapMark
  for things like "D.C.", "to Verses", "play 4 times", etc.
  that are usually right-aligned at the end of a bar.
  some defaults could be: 
    `((self-alignment-X . ,right)
      (break-visibility . ,begin-of-line-invisible)
      (font-shape . italic) (font-size . 0)) 


SectionMark   => \sectionMark
  for things like "Verse", "Bridge", "Refrain", "Coda", etc.
  that are usually left-aligned at the beginning of a bar.
  some defaults could be: 
    `((self-alignment-X . ,left)
      (break-visibility . ,end-of-line-invisible))


I think that having new grobs like these would make things
easier and more semantic (which I like).  And it would be
nicer to be able to define generic styles in a \layout block
instead of having to write custom music functions, or
repeatedly doing things like "\markup \bold \italic" or
whatever.

What do you guys think?

Thanks.
- Mark