Nine Inch Nails' latest album "The Slip" hit retail stores last week, but devoted fans have owned the tracks for months, and for free.

In May, the band released the album on its website with a note from lead singer Trent Reznor. "Thank you for your continued and loyal support over the years -- this one's on me," wrote Reznor.

And he's not the first to give fans free tunes. Music veterans Radiohead and Prince are also music heavyweights redefining the pay model of music online.

Nine years after Napster shook up the music industry, artists are now determining how and when to monetize sales, and giving consumers an opportunity to glimpse musical jewels without a price tag. "We put the artists and the label in control," says Ali Partovi, CEO of Seattle based iLike.

As artists and fans continue to restructure the age-old business model of record labels, some major outlets are struggling to generate album sales. But many are capitalizing on marketing platforms and Web sites that allow artists to make music available on their own terms.

For music-heads, take a look at where you can discover music online before a financial transaction.Seeqpod
This is a searchable Web site or the Google of music, that allows individuals to create a playlist from songs pulled from various areas of the internet. For instance, hard-to-find songs like Dinah Washington's "This Bitter Earth" can be heard on the web site that encourages adherence to the Digital Millennium Copyright Act. While this is not a hosting site, it's great for exposure to artists and can be used as a tool for research before buying.

AmieStreet
The independent music web site offers music for prices that varies, including free, based on popularity. Scandal vixen Ashley Dupre saw sales of her songs reach 300,000 following news of her affair with Eliot Spitzer. Imeem
A social media web site where users can post and listen to music from artists like Jason Mraz whose "We Sing. We Dance. We Steal Things" is currently online. Many major record labels have deals with the platform to allow streaming music from their artists on the web site.

YouTube
Each day hundreds, if not thousands, of songs are uploaded on the video sharing web site, allowing millions to discover and listen to songs. Songwriter and musician Ryan Leslie has utilized the video web site to introduce more than a half a million viewers of his YouTube channel to his yet-to-be-released album.

iLike
A music application with more than 30 million users, songs are available for free streaming and others for free download. Once a month, users can listen to 25 complete songs through Rhapsody. Country group Lady Antebellum used iLike, among others, for an online and digital campaign.

MySpace
With more than 100 million visitors, the social networking web site owned by News Corp. boasts a music section and pages from favorite and emerging artists like The Little Dragon, Karma, and Daughtry.

iTunes
Every Tuesday, the iTunes staff selects a song to offer for free under the Single of the Week category. Indie-cum-popular artists, such as Feist, Tegan and Sara and Sara Bareilles have all had a single featured in this weekly feature.