[3.5] Building a dragon - Confusion with CL, Abjurant Champion + Sublime Chord

[Kalfyra]

Hey there everyone! Been lurking at these forums for a time now. A wealth of information to be found here. wealth of information, and always a great thing to look up if I find a rules pitfall in 3.5. I ran into a pretty significant dilemma this time around, so I figured I'd put my inquiry out there to those of you who have a better grasp of the rules than I do.

If this has been posted before, I apologize in advance, for I could not find it, and would certainly appreciate the link to the discussion of which I've so overlooked!

Building class levels on a dragon ran into a snag. Many questions were raised that I had to ask myself to make sure everything was by the books. I like to avoid homebrew, and I do like to make sure my understanding of the rules is more in line with spirit than letter, but letter is just as important too.

Anyways, getting straight into it.
For purpose of this build, lets say this is a mature adult brass dragon. The class levels I am looking to apply to this brass dragon are Abjurant Champion 5, Bard 1, and Sublime Chord X. The main question about Sublime Chord pertains to caster level.
It has proficiency in one martial weapon and the feat Combat Casting.

First thing's first. I Noticed this little thing in the Draconomicon when I first began applying its class levels (emphasis mine on each quote from here on out, should they be bold.)

Although dragons cast spells as sorcerers, they are not members of the sorcerer class and receive none of that class’s benefits (except for spellcasting). A dragon gains bonus spells each day for a high Charisma score. A dragon that becomes a member of the sorcerer class adds any actual sorcerer levels it has to its effective sorcerer level to determine its spellcasting ability, but uses its actual sorcerer level and character level to determine its other class abilities. For example, an old silver dragon casts spells as an 11th-level sorcerer. If the dragon becomes a 1st-level sorcerer, it casts spells as a 12th-level sorcerer, but its familiar (if it has one) has the abilities of a familiar with a 1st-level master
Draconomicon, Magical Abilities, Pg.24

This is the question raised.
Because spellcasting progression is "+1 level of existing arcane spellcasting class," For a brass dragon with only effective sorcerer levels, Does a sorcerer class level become an unforeseen prerequisite in order to take Abjurant Champion class levels, for the brass dragon cannot advance its spellcasting?
Have I deduced this correctly, and if so or not so, why exactly?

That's my first conundrum!
Here's my second. How Abjurant Champion interacts with Sublime Chord levels.

On Abjurant Champion's caster level...

Martial Arcanist (Ex): At 5th level, you master the art of combining your militant and mystical training. From this point on, your caster level in a chosen arcane spellcasting class is equal to your base attack bonus (unless it would otherwise be higher).
Complete Mage, Pg. 50

Seem all fine and dandy. Dragon has obscene base attack score, caster level is gonna have tremendous benefits, like causing problems against dispel attempts and its own CL checks.

...But the real confusion set in when I began adding Sublime Chord Levels.

A sublime chord’s caster level for both her sublime chord spells and the spells she gains from other arcane spellcasting classes is determined by adding her sublime chord level to her level in another arcane spellcasting class.
Complete Arcane, Pg. 60

Now this is where I got really confused as to what the end result of caster level would be.

The end product I am assuming for caster level on this build would be...
------
Sorcerer caster level = Base attack. (Sublime Chord levels do not count, since the sum of levels, 9 levels of dragon spellcasting, potential sorcerer dip + Sublime Chord levels, is lower)
Sublime Chord = Only the sublime chord level itself? Or perhaps the 1 level of sorcerer added in the previous problem?
------

Am I mistaken on this, or is this all clear?

Thank you for your time everyone! I sorta sauntered into the forums on a gabby note, but I appreciate any assistance on the matter!

[Troacctid]

1. Yes, you need an actual class to advance.
2. Sublime Chord doesn't care about your caster level in the other class. Just your level. You're a 1st level sorcerer, so your sorcerer level is 1. As a Sublime Chord 10, you would therefore have a caster level of 11.

[Kalfyra]

Hmmmn... Son of a gray wasted yugoloth. That seems to confirm my suspicions.

Anyone else? think that I got the rules down pat to what my initial interpretations were on this dragon build?

[John Longarrow]

The line from Abjurant Champion is "At each level, you gain new spells per day and an increase in caster level (and spells known, if applicable) as if you had also gained a level in an arcane spellcasting class to which you belonged before adding the prestige class level." Since it specifies Class you would need to have a class for it to add to. One level dip in Sorcerer would allow for this.

At my table I'd let Abjurant Champion add to your Sorcerer casting, then add that to your Draconic casting. It isn't explicit in how this would interact, at least as far as I know.

[Kalfyra]

The line from Abjurant Champion is "At each level, you gain new spells per day and an increase in caster level (and spells known, if applicable) as if you had also gained a level in an arcane spellcasting class to which you belonged before adding the prestige class level." Since it specifies Class you would need to have a class for it to add to. One level dip in Sorcerer would allow for this.

At my table I'd let Abjurant Champion add to your Sorcerer casting, then add that to your Draconic casting. It isn't explicit in how this would interact, at least as far as I know.

I see. Looks like 2 for 2 on the unforeseen prereq sorcerer dip.

But I did always wonder if that was the spirit. But I suppose I can foresee even the spirit of the rules calling for a dip in Sorcerer on a Brass Dragon, seeing that it would call for formal training.

What's your take on the sublime chord and dragon spellcaster levels?

Edit: Actually, how they interact is explicitly stated in the draconomicon, that sorcerer levels stack with dragon spellcasting. So a dragon advances its spellcasting with sorcerer levels. As such, Abj.Champ should work for such additions, as 5 additional levels to sorcerer.