Move Change: notice closer to the bottom of the tune graphic. I was using \begin{center}..\end{center} to centre the tune graphic, followed by the change notice, if any. But this leaves a paragraph gap after the center section and hence a gap between tune graphic and change notice. Change to use figures to position the graphic, include the change notice as a caption, and use {\centering} around the image to centre just the image.

X: 1
T: Exploding Potato, The
C: Ed Pritchard
N: Change: ExtensionReel.abc
M: C
L: 1/4
K: Gmaj
"G" d B/G/ d B/G/ | d e d B | "Am" A>B c A | "D" D B c ^c |
"G" d B/G/ d B/G/ | d e d B | "D7" A>B c A | "G" G2 G2 :|
"D" A>F D D | "Em7" B>G D D | "Am" A B c e | "D" d B "G" [gBD] z |
"D" A>F D D | "Em7" B>G D D | "D7" A B c F | "G" G2 G2 :|