The music business remains in a state of turmoil. CD sales continue to fall. Untested business models emerge with the promise of new revenue streams. But as our fifth annual Money Makers ranking demonstrates, touring remains the most important income generator for most of the industry's top earners.

As the music industry grows ever more complicated, so does our top-secret* Money Makers formula. In past years, Billboard's Money Makers rankings were based on U.S. recorded-music sales, other U.S. revenue sources and worldwide touring data. In order to be as consistent as possible, this year's list is based solely on U.S. earnings-which explains why acts like U2, AC/DC and Metallica, which spent much of 2010 touring international markets, aren't included in this ranking.

TOP ALBUMS, SONGS, TOURS AND ARTISTS OF 2010

Still, the importance of touring varied sharply among those included on our list. Bon Jovi, which had the top-grossing U.S. tour of 2010, earned more than 90% of its total annual income on the road. At the other end of the spectrum, Susan Boyle generated most of her income from music sales. (She didn't tour the United States last year.) Eminem also did little stateside touring.

Our rankings take into consideration how much each artist earned from a wide range of income sources. In other words: We're looking here at closely estimated take-home pay. Net, not gross. The categories: touring; sales of physical albums, digital albums and digital tracks; tethered music downloads; on-demand music streams; noninteractive streams; and video streams. We compiled data on these categories for 2010, defined as the calendar year for Billboard Boxscore; and as the 52-week period ended Jan. 2, 2011, for Nielsen SoundScan data.

So, congratulations to everyone on the list-from Roger Waters to the Black Eyed Peas to Taylor Swift to Muse to, of course, Lady Gaga.

*Making Money Makers

Billboard editors used proprietary data from the Boxscore archives for U.S. concert grosses. We used SoundScan for sales of physical and digital albums and digital tracks. Data from Nielsen BDS provided information on tethered music downloads, on-demand music streams and noninteractive streaming at Myspace, Rhapsody, Napster, AOL, Yahoo, Slacker, MediaNet, Guvera and Thumbplay. Also included in our calculations were Vevo video plays, as well as video data compiled by online tracking service TubeMogul for Myspace, YouTube, Metacafe, Dailymotion and other video-hosting sites.

Corresponding mechanical rates and estimates were applied for each of the aforementioned categories. In calculating an artist's share of revenue from recorded-music sales, we assumed a royalty rate of 20%, minus producer fees. Artists received 100% credit for the sale of a title or concert Boxscore if credited as the lead artist and 50% credit if they shared equal billing with another artist. An example is the James Taylor/Carole King shows: We split the gross in two and calculated from there. We credited each artist with 34% of gross tour receipts (what's typically left after the promoter's fee, the artist manager's fee and other costs are subtracted).

An artist's take of revenue from on-demand streams was calculated based on the average wholesale rate paid to labels. Revenue from noninteractive streams was based on SoundExchange's rate settlement with webcasters. An artist's share of revenue from tethered downloads was calculated on the number of plays. In instances where the artist is a songwriter, Billboard estimated the share of songs written by that artist.

CD mechanical royalties for artist/songwriters were calculated by assuming the standard royalty rates. For digital album and track downloads, we used the current statutory rates, assuming 12 tracks per album. We also subtracted a 10% manager's fee for each revenue category.

What our figures don't include: revenue from merchandise sales, sponsorships, synchronization deals, international tour dates, songwriter performance royalties from terrestrial radio play, DVDs and ringtones. Why? There just isn't enough of that kind of data available across the whole board.

The data used in this report was compiled and calculated by Billboard senior correspondent Ed Christman, research manager Gordon Murray, senior editorial analyst Glenn Peoples and Boxscore chart manager Bob Allen. All song and album sales numbers mentioned are according to Neilsen SoundScan unless otherwise noted.

Text by Ray Waddell, Cortney Harding, Monica Herrera, Jillian Mapes, Mariel Concepcion, Mitchell Peters, Louis Hau, Gail Mitchell, Deborah Evans Price