You can even ask for a specific song by a specific artist, "Alexa, play Money for Nothing by Dire Straits." If the song is in your library--or Amazon's--the song will start playing. If the song isn't in those libraries, it might at least play a 30-second sample. (Including the artist's name is the best practice when asking for standards, such as "My Funny Valentine," because you might get an instrumental version if you don't.) Surprisingly, the Echo would not fulfill requests to play specific artist's albums.
Amazon wisely doesn't limit you to using its own Amazon Music and Amazon Prime Music services, but it currently doesn't give you a lot of other choices, either: You can use voice commands with your Pandora, iHeartRadio, and TuneIn accounts, or you can pair your smartphone or tablet using Bluetooth and stream music from any source available to that device. The Echo supports the Advanced Audio Distribution Profile, aka A2DP. I'll go into more depth about the Echo's Bluetooth capabilities later.
The Echo app
You can control the Echo from a PC using a browser-based interface, or you can install the Echo app on smartphone or tablet (there are versions for Android, Fire OS, and iOS). You can use either to control the timer, the alarm clock, and your to-do and shopping lists (you can add items to these lists with your voice, but you must use a browser or the app to remove them). I checked out the Android and iOS versions of the Echo app in addition to using the browser-based UI on a Windows PC.
As I mentioned earlier, you can also control the Echo's music-player functions over a Bluetooth connection, or you can stream music from your computer or device (including the services running on it, such as Apple Music, Spotify, Tidal, or what have you) to the Echo.
You can control music playback using the Echo app or whichever other app you're using to play music. Voice commands issued to the Echo (play, pause, resume, etc.) are relayed back to the device over the same Bluetooth connection, using the Bluetooth Audio/Video Remote Control Profile (AVRCP). Bluetooth connections from a Mac running OS X, however, are not supported.
In addition to controlling the Echo, the browser and device apps maintain an audit trail of every voice command and the results. This history includes all the songs you've played (not including tracks streamed via Bluetooth), links to news headlines, sources of answers to trivia questions, and in some cases, links to search engines. Poking through this series of events will tell you a lot about what the Echo can and cannot do.
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