In English the preposition "to" is necessary in a sentence with this structure. "I am listening to music, to the radio, to my mother., etc." If you don't specify what it is you are listening to, you may say "listen" without "to": A mother asks her child, "Are you listening?" ("to me" is implied.) But note that I said, "If you don't specify what you are listening to…" Here "what" takes the place of music, etc., so "to" is necessary.
This is the question about the English continuous and progressive aspect, which does not really exist as such in Russian. Instead, Russian uses perfective (done as a one-time event) and imperfective (done regularly over a longer span of time) aspects. "Do you listen to" implies something done regularly, and thus would use the imperfective verb слушать. "Are you listening to" implies something being done right now, and thus would use the perfective verb послушать.
Of course we aren't. I'll try to explain the correct tone of this sentence. By letter N I'll signify 'normal tone' (with which you are starting the sentence).
So 'Ты' is pronounced in N. On the first syllable of the words 'слушаешь' (слу-) the tone is rising, and then slowly falling to the end of the word to N. Then everything is pronounced in N until the last syllable of the sentence (классическую музы-), and on the last syllable (-ку) a little bit falling.