We're still not sure whether Amazon's truly launching a music streaming service, but if it does, you might only be able to access songs and albums for a limited time. According to the Wall Street Journal, the e-commerce company hopes to offer music streaming as part of Prime to justify an annual membership (from $79 to $119) price increase. Unlike other services like Spotify or Pandora, Amazon's end goal is to entice people to download tracks from its MP3 store, hence, the time limit. Meanwhile, Billboard reports on rumors compiled from sources at multiple labels, where Amazon's apparently going after older titles, and proposing smaller, capped payments based on the number of plays. The service's existence depends on whether Amazon and recording companies can agree on licensing fees, though -- it's reportedly far from being a done deal.