Can mp3s be purchased online with "no strings attached"?

I purchased some mp3s online only to have them not be playable without downloading a “music library” application? I tried deleting the brand name music library app and found my purchase was no longer in my iTunes library. Is it possible to purchase mp3s without having to sign over your firstborn child? (enter a binding contract) So far there are too many hoops and strings attached. Or is this the price we pay with the monopoly of our big tech/s?