Starting today, Zune users subscribing to the $15 a month Zune Pass service will get to also keep 10 tracks a month of their choice as a permanent download.

Previously the Zune Pass worked like any other subscription service, where users paid the monthly fee for unlimited access to all 4 million songs in the Zune database. However access to those songs, as well as the ability to play any tracks downloaded, would disappear should users stop paying the monthly fee. Also, they would only play on the Zune device.

The 10 songs a month downloaded under the new offer, however, don't have those same restrictions. Microsoft has agreements with all four major labels and indie aggregators The Orchard and IODA to make their content available, in total representing about 70% of the Zune catalog. The remaining 30% is expected to come online once the company finalizes licensing deals with a range of other indie labels.

According to Zune GM of global marketing Chris Stephenson, the new deal is designed to lure more users to the subscription model. He says consumer research studies conducted by the Zune division shows music fans need something more to convince them to pay $15 a month for music, such as the ability to keep and own music discovered through the service.

To make the offer, the Zune team had to rework its existing licensing deals with labels so that it now provides a certain percentage of the Zune Pass subscription fee to all labels based on market share, and then allocates a separate payment to each label based on what music is downloaded for good.