Construct harmonious tunes in line with the outlined letter symbolism and the presented thematic component.
X:1
L:1/8
M:2/4
K:Bb
['B e d f (dB)', 'd f']  
X:1
L:1/8
M:2/4
K:Bb
"^A" B B B e | d f (dB) | F F F B | A c (AF) | B A B e | d f (dB) | c e c A | B2 B2 || 
"^B" d f d B | d f d2 | c e c A | c e c2 | d f d B | d f d2 | c e c A | B2 B2 |]  