A sings Ba

We bought a phonics book for Nila today. She was looking at the S sings "snake" page and singing the below song:

A sings 'ba', A sings 'ba'

Every letter has a sound 

and A sings 'ba'

B sings 'ba', B sings 'ba'

Every letter has a sound

and B sings 'ba'

C sings 'ba', C sings 'ba'

Every letter has a sound

and C sings 'ba'

Every letter has a sound - who told it has to be a different sound. And some people claim she does not know phonics. Ha.