Yes, really. In this video, we'll look at how you can use Audacity to generate actual radiofrequency signals. We'll look at mono AM and FM, as well as stereo FM (the Zenith/GE system we all use nowadays), and we'll also look at the infamous C-QUAM AM stereo system that's sometimes seen on the air but rarely heard. Audacity's maximum audio bandwidth is somewhat limited, but, 384khz is enough (although a 192k broadcast FM signal maxes it out).

We'll use SDRuno and SodiraSDR to demodulate the signals. I apologize for messing up with the AM stereo demo :(

Also, if you have a GOOD soundcard that can output a signal with 192 KHz of audio bandwidth at a 384 KHz sample rate, you can run that into a double-balanced modulator (with the carrier being generated by a signal generator or an RF oscillator of some kind) and then out the air. Of course, this isn't a real-time solution at all; if you need a real-time solution, check out GNUradio.