To say that something is the smallest or the most beautiful, first think about the gender of the thing, then use leplus, laplus, or lesplus before an adjective.
C'est le plus petit chien !
He's the smallest dog.
C'est la plus belle femme du monde !
She's the most beautiful woman in the world.
Ces chiens sont les plus rapides.
These dogs are the fastest.
Mon village est le plus joli de France.
My village is the prettiest in France.
J'entends de la musique
To say that you hear something, use du, de la, or des before the thing that you're hearing.