> Something you hear often in the jazz community, especially from experienced pros is "everything you need to know about theory is in the songs".

The advice of just listen/play music that I often read is imho a bad advice. You would not give people data about orbits and expect them to discover by themselves newton's law without never teaching the laws.

Of course music theory is not a scientific theory, and not only theory by itself is not enough (in both cases) but too much theory before practice is bad. And of course listening and practicing a lot of music is extremely important.

But who is going to progress faster: the student that knows what a chord is and how they are built or the student that is just listening to music ?