Amazon is introducing its answer to Spotify and Apple Music, and it's playing to win.

Amazon on Wednesday launched Amazon Music Unlimited, its on-demand streaming service. The new offering is priced aggressively, with Amazon Prime members able to subscribe to the service for $7.99 a month — below the $9.99 rate popularized by Spotify, Apple Music and just about every other major music streaming option.

The on-demand streaming service will work online and through a redesigned Amazon Music app as well as through the Amazon Echo. A separate for-Echo-only streaming plan will cost $3.99 a month.

Prime subscribers can elect to pay a flat $79 for the year to join the service, rather than the $7.99 monthly fee. That brings down the cost to $6.58 a month.

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Amazon already offers some music streaming to Prime members, but its full launch of Amazon Music Unlimited expands that music library from about two million songs to "tens of millions," Amazon said in a press release. To gain access to the full catalog, Prime members will have to join Amazon Music Unlimited.

Spotify and Apple Music claim to have more than 30 million songs in their libraries. An inquiry to clarify Amazon's library was not immediately returned.

For people that already have Prime and a streaming service like Spotify, the new offering could save consumers around $24 per year if they switch.

Amazon is continuing its effort to hook more Prime members, who spend 4.6 times as much on Amazon every year than non-subscribers. Just last week, Amazon added free access to some of its e-book library as the latest perk for Prime members. Music streaming is now just one more thing Prime subscribers don't need to leave Amazon to get.

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Amazon's launch of a full music streaming service has long been rumored. The tech giant is one of several companies — Pandora, iHeartRadio, Vevo — trying to compete with the biggest music streaming players. Pandora just introduced a $5-a-month ad-free radio service that hopes to draw some customers with its lower price.

But Amazon is the only one that already has subscribers on board.

The version of Amazon's new service that is linked to Echo is powered by Amazon's virtual assistant, Alexa. Users can use voice control to choose streamed songs or browse Amazon's music library.

Right now, Amazon's music streaming subscription is for one user, but the company plans to introduce a family plan that will license up to six accounts for $14.99 a month.