Derriten comes from the verb derretir, which means 'to melt'. It's a fantastic word to learn because of its vivid, poetic use in this song.
Monsieur Perine sings "Cuando bailas brillan las estrellas / Todas se derriten sobre el mar" (When you dance the stars shine / They all melt over the sea). This beautiful image suggests a moment so magical and intense that even the stars are overcome, 'melting' into the ocean from the beauty of the dance.
This song is all about that electric feeling of wanting to be with someone so badly you can barely stand it. The singer spends her time just imagining this person, admitting she's been "sola aquí esperándote" (alone here waiting for you). There's this incredible tension where they're both aware of each other, but not quite connecting: "Y tú, mirándome sin hablar / Y yo, hablándote sin mirar" (And you, looking at me without speaking / And I, talking to you without looking). It's that shy, nervous energy before anything happens, and she feels like she's dying from it!
The whole song builds up to one simple, perfect solution: dancing. The chorus is a plea to just let go and "Bailar contigo, y perdernos esta noche" (Dance with you, and get lost tonight). It's about forgetting the world and connecting on the dance floor, with the sounds of "la arena y los tambores" (the sand and the drums) in the background. She sees this person as having "la llama que enciende mi alma" (the flame that lights my soul), a connection that feels almost magical and destined.