I used Google Play Music when it first came out with the 7.99 offer and it simply matched my music...though, it doesn't have everything because it would break. I haven't seen a service that moved the music from the hard drive to the cloud unless you explicitly tell it to ( like Google Drive). Amazon Music uses matching: "Music that is matched to Amazon's catalog by Amazon Music for PC and Mac is delivered as a high-quality 256 Kbps MP3. This feature may not be available for all music in our catalog, as eligibility may be limited. Music that is not eligible for matching includes: Songs for which we don't have rights to provide this feature Songs that are not in Amazon's catalog Songs with file formats that are not supported In some cases, this may cause only part of an album's song list to be matched and delivered to My Music. Songs or albums not currently eligible for matching (with a supported file format) will be uploaded instead. Note: Matched music is delivered as a 256 Kbps variable bitrate MP3 regardless of whether the original audio quality is higher or lower than 256 Kbps." Amazon.com Help: About Matched Music Amazon also has cloud storage, but that is not what I am referring to, but I don't know about the OP.