Escuchar a

Escuchar a
 

Is “escuchar a” only used when you are listening to a person (i.e. the personal ‘a’)?
Tenemos que escuchar a Juan.

Would this make the use of ‘a’ as a preposition incorrect in the sentence below?

“Después de un concierto allí, salió de fiesta a una discoteca y escuchó por primera vez a la canción.”

I always thought the preposition ‘to’ in ‘to listen to’ (the second ‘to’ here) was already built into the verb ‘escuchar’.


Many thanks in advance.

Your understanding is correct.
The personal 'a' is needed when the direct object is a person (and the preposition is tied to the person, not the verb). Otherwise, no preposition is needed prior to saying the direct object.

Thank you, Rusty.
Would a native speaker make this mistake? I'm almost certain that I heard a native use 'escuchar a' followed by 'la canción' recently.

All native speakers make mistakes, in every language.

@fglorca: You wouldn't believe the many mistakes native speakers make. :D