We are asked this question a lot.
iTunes, Apple, Spotify, Amazon, and many others may not accept your music directly, however a distributor that has a partnership with these and other Digital Service Providers can bring your content online through their stores.
Music Distribution isn't as easy as sending an MP3 or a CD via the mail, you have to be able to create XML files and meet specific and often complicated technical standards just to get music distributed.
A musician should be and is focused on their art form and getting exposure and shouldn't have to employ a team of programmers, marketing experts, and support representatives to be able to do what they do. That is why you can have Symphonic handle your distribution. You just upload your music in one place and we take care of the grunt work of actually delivering it to every partner in the music industry.