Formulate chord sequences to heighten the harmonic quality of the specified musical portion.
[BD][cF] | [dB]2 [BF]2 [dB]4 | [fd]2 [dB]2 [fd]4 | [ec]2 [Ac][ge] [fd][ec] | 
 [dB][ec] [dB][cA] [BG][cA]"^I" | [dB]2 [BF]2 [dB]4 | [fd]2 [dB]2 [fd]4 | 
 [ec][dB] [cA][BG] [AF][cA] | [BB]2 z2 :: [BF][dB] | [fd]2 [dB]2 [fd]4 | 
 [ec]2 [cA]2 [ec]4 | [dB]2 [BF]2 [dB]4 | [cA]2 [AF]2 [cA]4 | [dB]2 [BF]2 [dB]4 | 
 [fd]2 [dB]2 [fd]4 |1 [ec][dB] [cA][BG] [AF][cE] | [BD]2 z2 :|2 
 [ge][fd] [=e^c][fd] [_e=c][cA] | [BB]2 z2 :|  
X:1
L:1/8
M:34/44
K:Bb
 [BD][cF] |"Bb" [dB]2 [BF]2 [dB]4 | [fd]2 [dB]2 [fd]4 |"F7" [ec]2 [Ac][ge] [fd][ec] | 
"Bb" [dB][ec] [dB][cA] [BG][cA]"^I" |"Bb" [dB]2 [BF]2 [dB]4 | [fd]2 [dB]2 [fd]4 | 
"F7" [ec][dB] [cA][BG] [AF][cA] |"Bb" [BB]2 z2 :: [BF][dB] |"Bb" [fd]2 [dB]2 [fd]4 | 
"F7" [ec]2 [cA]2 [ec]4 |"Bb" [dB]2 [BF]2 [dB]4 |"F7" [cA]2 [AF]2 [cA]4 |"Bb" [dB]2 [BF]2 [dB]4 | 
 [fd]2 [dB]2 [fd]4 |1"F7" [ec][dB] [cA][BG] [AF][cE] |"Bb" [BD]2 z2 :|2 
"F7" [ge][fd] [=e^c][fd] [_e=c][cA] |"Bb" [BB]2 z2 :|  