How do I get chords that last half a measure to display correctly in 6/8 in LilyPond / Frescobaldi?

Question

I am currently using a lead sheet template to make a reference lead sheet for someone (I am looking to see if the chords that I found are correct, but that is a whole other problem). In LilyPond / Frescobaldi, I cannot get the chords to the C Section to display properly. I may just put them in as text, but for future reference I would like to know what I am doing wrong. Here is what I have so far (the C section is set off by asterisks, just so that you know that they were not originally in LilyPond) :

\version "2.19.55"
\header {
  
title = "Spartacus Love Theme"
  
composer = "Alex North" 
subtitle = "Original Movie Version"
}

\language "english" 
melody = \relative c' '  {
  \time 6/8 
\key a \minor
 \partial 4 a8 e' 
\repeat volta 2 
{  c4.~ c8 a e' 
c4.~ c8 a b 
c4 a8 c4 d8 
d c4 r8 a8 e' 
c4.~ c8 a8 e' 
c4.~ c8 a8 b 
c4 a8 c4 d8   } 
\alternative { {  e c4 r8 c g'  \bar "||" 
e4. d8 a d 
e4. r8 c g' 
e4. d8 a d 
e4. \fermata r8 e fs 
g4. r8 fs e 
fs e4 r4 e16 a 
g4. r8 fs e 
fs4. r8 fs g 
a4.~ a8. g16 f[ e] 
d4.~ d8. c16 b[ a] 
gs4.~ gs4. 
g4.\fermata ~ g8 a\fermata e'\fermata } 
{  e c4 r8 a e' 
c4.~ c8 c g' 
e4.~e8 f, c' 
a4.~ a8 bf g 
a4. r8 a8 e' 
\key a \major cs4.~ cs8 a e' 
cs4.~ cs8 a e' 
cs4. b8 fs b 
cs4.~ cs8 a e' 
cs4.~ cs8 cs gs' 
e4.~ e8 a, e' 
cs4.~ cs8 a e' 
cs4.\fermata~ cs8 a\fermata e'\fermata
cs4.~ cs8 a e' 
cs4.~ cs8 a e' 
cs4. b8 fs b 
cs4.~ cs8 a e' 
cs4.~ cs8 a e' 
cs4.~ cs8 a e' 
cs4.~ cs8 a\fermata e'\fermata 
cs4.\fermata~ cs4. 
cs4.\fermata~ cs4. \bar "|." } }
}
 
harmonies = \chordmode { r4  d2.:m7 a2.:m7 d2.:m7 a2.:m7                         
f2.:maj7 e2.:m7 d2.:m7    c2.:maj7  
f2.:maj7 c2.:maj7 f2.:maj7 cs2.:m9 
e2.:m7 e2.:m7/d e2.:m7/c b2.:9- 
f2.:maj7 bf2.:maj7 e2.:9- a2.:7  
c2.:maj7

**f2.:maj7 d4.:maj7, bf4.:maj711+, g4.:maj9, and ef4.:7 fs2.:m7/a 
d2.:maj711+ b2.:m9 g2..:maj711+ a2..:maj711+ 
fs2.:m9 d4.:maj9 b4.:m9 g4.:maj9 ef4.:m75- a2..:maj711+  
d2.:maj711+ b4.:m9 g4..:maj711+ ef4.:m75- e4.:7 a2..:maj711+                         
d4.:maj7 d4.:m7 cs4.:m75- fs4.:7 b4.:m7 ef4.:m75-  a2.:maj7 a2.:5**                        
} 
 
\score {  
<<    
\new ChordNames {
\set chordChanges = ##t
\harmonies
}

\new Staff \melody  
>>
  
\layout{ }  
\midi { }
}

Answer 1

**f2.:maj7 d4.:maj7, bf4.:maj711+, g4.:maj9, and ef4.:7 fs2.:m7/a 
d2.:maj711+ b2.:m9 g2..:maj711+ a2..:maj711+ 
fs2.:m9 d4.:maj9 b4.:m9 g4.:maj9 ef4.:m75- a2..:maj711+ 
 
d2.:maj711+ b4.:m9 g4..:maj711+ ef4.:m75- e4.:7 a2..:maj711+                         
 
d4.:maj7 d4.:m7 cs4.:m75- fs4.:7 b4.:m7 ef4.:m75-  a2.:maj7 a2.:5** 

I see a couple of commas and the word 'and' there which cause compilation errors for me. When I remove them, it compiles. (I assume you already did this in your original scoresheet.)

Now, sometimes you have two periods instead of one, e.g. in the second line:

g2..:maj711+ a2..:maj711+ 

which may be the cause of your problems. 2. produces a chord of length 6/8, but 2.. produces one of duration 7/8, e.g. slightly more than one bar. This pushes the subsequent chords to the right; therefore they don't line up with the melody anymore.

You may be able to spot problems like this during compilation by consistently using bar symbols (|) throughout your melody and chords, wherever you expect a measure to end. At least, that has saved me a couple of headaches already. See the manual, section Bar and bar number checks, for more details. Simply putting a | between g2..:maj711+ and a2..:maj711+ gives:

test.ly:124:33: warning: barcheck failed at: 1/8
d2.:maj711+ b2.:m9 g2..:maj711+ 
                                | a2..:maj711+

so it tells you exactly where your (first) error is.