Amazon was one of the first services to offer uploading your MP3 collection into the cloud, but this was officially discontinued in 2018. Meanwhile, both the Apple and YouTube services allow you to combine your personal music collection with the streaming catalog, though tagging and organization can be a time-consuming challenge (your myriad live Phish tracks won't organize themselves). Still, if you've invested money in digital music over the years, those two services offer a patch to continue enjoying that music online.