Change text font size globally

[Dimitri Sykias]

How can I change the text font size globally and independently of the staff 
size, dynamics, lyrics etc.?
Here is my Preamble:

\version "2.24.4"
\paper { 
  #(define fonts 
     (set-global-fonts 
      #:music "emmentaler" 
      #:brace "emmentaler" 
      #:roman "Minion Pro"
      #:sans "Edwin"
      #:typewriter "MusAnalysis" 
      #:factor (/ staff-height pt 20) 
      ))  
  #(define-markup-list-command (paragraph layout props args) (markup-list?)
     (interpret-markup-list layout props
                            (make-justified-lines-markup-list (cons 
(make-hspace-markup 2) args)))) 
  top-margin = 1.6 \cm
  bottom-margin = 1 \cm
  left-margin = 1.8 \cm
  right-margin =1.8 \cm
  ragged-bottom = ##t
  ragged-last-bottom = ##t
  print-page-number = ##t
  first-page-number = 1
  oddHeaderMarkup = \markup \override #'(font-name . "TeX Gyre Pagella Bold")
  \fill-line {
    ""
    \unless \on-first-page-of-part \fromproperty #'header:instrument
    \if \should-print-page-number \fromproperty #'page:page-number-string
  }
  evenHeaderMarkup = \markup \override #'(font-name . "TeX Gyre Pagella Bold")
  \fill-line {
    \if \should-print-page-number \fromproperty #'page:page-number-string
    \unless \on-first-page-of-part \fromproperty #'header:instrument
    ""
  }
  score-markup-spacing.basic-distance = 8
}
\layout {
  indent = #4
  #(layout-set-staff-size 20)
  ragged-last = ##t
  \context {
    \Score
    \consists "Horizontal_bracket_engraver"
    \override HorizontalBracket.direction = #UP
    \override HorizontalBracket.thickness  = 2
  }
  \override LyricText.font-name = "Edwin"
}
% HEADERS
\markup headerA = \markup \huge \bold \with-color #(x11-color 'darkred) \etc
\markup headerB = \markup \larger \bold \with-color #(x11-color "SteelBlue4") 
\etc
\markup musa = \markup \override #'(font-name . "MusAnalysis") \etc
\markup mgly = \markup \override #'(font-name . "MusGlyphs") \etc
yes=^\markup { \with-color #darkgreen ✔ }
no=^\markup { \with-color #red ✘ }
strong = ^\markup {\fontsize #3 "–"}
weak = ^\markup \raise #0 \rotate #-90 ")"

% HEADER
\header {
  title = \markup { \magnify #1.4 \with-color #grey {Τροπική Αντίστιξη} }
  subtitle = \markup { \magnify #1.4 \with-color #darkblue {Γενικές Έννοιες}}
  copyright = "3euk1L4 • 2024"
  tagline = ""
}
\include "roman_numeral_analysis_tool.ily"

Thanks for your help!