Years ago, I wrote a Chrome extension for Google Play Music that has since amassed about 70k users. Today that extension was removed from the Chrome store pursuant to a DMCA request from the National Music Publishers' Association. The extension in no way infringes on the copyright of any material. There's no way of interpreting things in which you could claim that it does.
The extension added notifications and playback controls to Google Music in Chrome. Years ago it also allowed users to download (their own) music, but it doesn't even do that any more.