How do you enlarge the chord name size?

[JD Brennan]

I'm trying to enlarge the chord name size. 

I figured out how to enlarge the note name, but not
the alteration name.  I'm not sure what the LilyPond
terminology is, but from looking at the code it
looks like note name refers to "C" in "C7" and
alteration refers to "7" in C7.

    \context ChordNames {                                      
        \property ChordNames.chordChanges = ##t 
        \property ChordNames . ChordName \override #'font-relative-size = #+3 

makes the note name larger (the C), but the 
alteration (the 7) is still small and superscripted.

I can't figure out where in the Lilypond code the
superscript happens, but it must change the font
also.  I don't think I need the superscript, but I
really want to just change the font size.  Checking
my Real Book, the hand written chords do slightly
superscript the alteration most of the time, but the
font size is hardly any smaller.

Thanks for any pointer to where I could look for
this.  I'm running Lilypond 2.0.1 on OS X.

Really like LilyPond.  Way cooler than other
notation software I've tried!  Every other
notation software I've tried took longer than
doing charts by hand and never looked as good.
Not so with LilyPond!  I think I can actually do
a chart faster now!

JD