Construct a harmonious chain of chord progressions that enhance the presented musical piece.
Aab | Bcd | Cef | | | | |"^tempo rubato" |]  
X:1
L:1/8
M:4/4
K:A
 Aab | Bcd | Cef | |"A7" |"Bb" |"Cm" |"^tempo rubato" |]  