Not nearly as much as you might think. It's hard to quantify because there are so many variables...and in certain formats, maybe it's possible to retire off of one hit. The problem is, in the genres that pay more, you rarely if ever see a solo written song....some current hits have double digit writers. I saw one rap song that had 39 writers listed.

In the country format, you could possible gross $1 million....but that has been dropping substantially over the past few years and I think it's probably closer to $600-750k. The tax bracket that amount would throw you into means you'd net around half of that. Keep in mind also that the numbers I'm giving you are the total gross of the song....both the writing & publishing share. And the business reality is, the possibility of a solo written, writer published song (where you keep 100% of the ownership) is mathematically impossible. You would wind up having to give up, at a minimum, part or all of the publishing, or allow one or more writers to "tweak" your song and get an equal share. The net clearly drops proportionally.

In the past, the performance income of a hit was enhanced by mechanical royalties. A Garth Brooks hit in his heyday could net you a fortune - not only did he get tons of airplay, he had albums selling 8, 9, 10 million or more units. Well, mechanicals are dead in the water - nobody much buys physical product anymore, nor do they buy mp3s. It's almost all streaming - and of all the rapings songwriters have gotten over the years, the royalty structure for streaming is one of the most egregious.

My friend that I mentioned who is the songwriter HOF called me this morning, and we were discussing this. I asked him if he thought someone could retire off of one hit, and he laughed...hard.

One of the things that really bugs me these days is the number of people who have set up businesses that do little other than "sell the dream" of making it big in songwriting. What they're really doing is "selling the myth", or at best "selling how it used to be". The number of songwriters in Nashville making a truly decent living from songwriting alone is less than 100....substantially less. It has become less and less of a viable profession, and I think in my lifetime will cease to be one. We've pretty much all become professional hobbyists. I've been able to sustain myself from a combination of past royalties, current activity (mostly in alt markets like bluegrass, Americana, & red dirt), producing a few acts, and TV/film synch stuff. I'm also at a stage of life where I'm ok with that and place more value in doing what I love than trying to make a bunch of money doing something I despise.

Longer answer and more info than you probably wanted, sorry....I got on a roll.

http://www.rogerbrownsongs.com
http://www.nashvillesongwriters.com/roger-brown