Can you import previously downloaded songs into your Amazon Music library?

I gave up on that - at the advice of my adult (40) son who has an MM degree in audio and digital music.  He just said "How hard it is it to just keep Amazon and iTunes both on your devices?  Get over it, Mom."  These companies are clearly competitors - and the internal coding of each selection causes ENOUGH problems as it is. Some things will ONLY be visible by the coding of the seller, etc. - and there is nothing you can do about it, no matter how you think you can change the names, etc. This has been discussed here a lot, before.   I maintain massive databases of over 5,000 CDs,(let go of the huge vinyl collection . . ) and many thousands of pages of sheet music and music books (we are career professional classical musicians, and ran an agency for decades, for commercial classical gigs, as well as our concert lives.)  Not all pieces of music, in ANY format, are gonna fit the way you want to keep track of them.  So now, I know what kinds of things are best handled where - and moved on.  And as advised - for enough $$, work-arounds will appear.

At one time Amazon did allow you to upload music that you had purchased from other sites, but this is no longer available in the free version. The paid version will allow you to make play lists but I'm not sure the later is even available on the paid version..I think that soundcloud will allow you to do these things on a limited basis in the free version but if you have a huge playlist of music to upload you would need the paid version of soundcloud...