The only problem with this argument is that it's made only with regard to you, the consumer, vs. the content creator/distributor. If theft is defined only as the removal of a physical good from one individual to another without consent, then indeed, it's not theft in that sense. However, if theft is defined as depriving an individual of what they are due for providing some product/service, then this is theft.

One way or another, somebody took the time to learn to play some instrument, write a song, record that song, then get it distributed in some manner. All of that costs both time and money, just like designing and building a car or a laptop or any other physical good. If depriving someone of compensation for something they worked to create and distribute isn't theft, I don't know what is.