Eric, you seem to have such a propensity for “prolific creativity,” as well as for giving valuable things away, that I think you should be aware that you could be arousing suspicion. Suspicion that the material actually does not belong to you, and that someone who innocently uses the tracks might wind up on the wrong end of a copyright lawsuit.
(The laws are so draconian that one rap artist’s diligent lawyer insisted on receiving a copyright release for a sampled chord, even though the owner of the song could scarce believe it.)
To put it another way: people might not “suspect” you, or suspect “you,” but the laws are such that they literally cannot afford to take any risk. As a seller or even a giver-away of intellectual property, you must take pro-active steps to address that concern.
Now, you just might be a great musician who doesn’t know the market value of what he’s doing, but copyright issues are nothing to fool with. Do you have, say, US Copyright Registration numbers on all of these tracks (or collections), that we could look-up and verify? Registrations that were secured before the date that the tracks first appeared anywhere? (You can register a “collection,” of as many songs as you like, all at once, for $35 per collection.)
This might sound “harsh” or even “rude” to you, but remember, I live near Nashville, TN. “Music City, USA,” and probably the biggest hive of intellectual-property attorneys this side of L.A. People do “think like that.” No one will touch your music unless you can prove your assertion that you own it, and major projects still “sample the airwaves” before using anything. Because they know that, if somebody comes out of the woodwork with a claim and the paper to back it up, “they’re dead meat, that’s all.” Pants down. Game over. Utterly screwed.
If everything’s hunky-dory and you simply haven’t gotten around to it, go register everything now. And, start referencing the registration-numbers prominently. It’s called “due diligence,” and it is extremely important. It isn’t enough for you to merely “say” that the music is free, let alone for commercial(!) use. No one, most-especially in a real commercial project, can afford to rely merely upon that.