Invent engaging chord sequences that bolster the harmony of the existing music.
f |: gd ef/e/ | dB cd/c/ | BG AF | G/A/B A2 | gd ef/e/ | 
 dB cd/c/ | BG AF | GB G2 ::[K:D] Ge/G/ Ff/d/ | Ge/c/ fd | 
 Ge/G/ fd | af g2 | Ge/G/ Ff/d/ | Ge/c/ fd | Ge/c/ fd | 
 Bc d2 :|  
X:1
L:1/8
M:2/4
K:G
 f |:"G" gd"C" ef/e/ |"G" dB"D" cd/c/ |"G" BG"D" AF |"G" G/A/B"D" A2 |"G" gd"C" ef/e/ | 
"G" dB"D" cd/c/ |"G" BG"D" AF |"G" GB G2 ::[K:D]"A" Ge/G/"D" Ff/d/ |"A" Ge/c/"D" fd | 
"A" Ge/G/"D" fd |"D" af"C" g2 |"A" Ge/G/"D" Ff/d/ |"A" Ge/c/"D" fd |"A" Ge/c/"D" fd | 
"Em" B"A"c"D" d2 :|  