Instead of using a traditional search box and typing in song titles, users will now be able to ask for them on the Amazon Music app on Apple's iPhones and iPads, as well as Android smartphones.
But as well as searching for a favourite song, it is understood it will add full Alexa functionality to smartphones for the first time outside of the US. That means questions such as "what's the weather" can be found from phones in the same way as you currently can on the Amazon Echo, Fire tablet and other devices,
Apple's iPhone comes with the built-in Siri voice assistant, while Google Assistant is available on Android phones, both of which can offer weather forecasts and more when asked. Samsung has also stepped into the voice assistant fray with Bixby, which is built into its latest handsets.
Users will tap a button to trigger Alexa before speaking to the Amazon Music app. The streaming service rivals Spotify and Apple Music. It launched in the UK last year - the latest Alexa integration is being pitched as a push for the streaming service.
Paul Firth, the UK head of digital music at Amazon, told City A.M. Amazon is "very pleased" with how well the service is doing, adding that it's "ahead of where we expected to be". The tech giant does not release user numbers, but according to music industry analyst Mark Mulligan it is now the third largest subscription service in the world behind Spotify and Apple.
Alexa will also let users search in new ways not typically available via typing, responding to phrases such as "play the latest song from Foo Fighters" or "play Oasis songs from 1995". Commands informed by how people interact with playing music via the Echo are "a more natural way to search", said Firth.
He added that he was confident Alexa on smartphones will be used outside the confines of the home, and even among people on the commute listening on headphones, as voice assistant use grows and becomes the norm.