Amazon is now offering the option to US customers to access Amazon Prime Music service without having a Prime membership or Amazon Music Unlimited subscription. But before you rush to try the service, it comes with quite a few caveats. First of all, it is ad-supported, which should be expected but still worth mentioning. Second, and more importantly, it only works on Alexa-enabled devices, such as the Amazon Echo products, Sonos One, etc. This means you won't be able to play it through any of the Prime Music apps on any platform or the web. Lastly, you can't just play any...