That is because the majority of the music that was released last year was good.

Album Sales Post First Yearly Gain in Four Years
LOS ANGELES (Reuters) – Led by Usher’s blockbuster release “Confessions,” U.S. album sales rose nearly 2 percent in 2004 — posting their first gain in four years even as digital music downloads continued to explode, Nielsen SoundScan reported on Wednesday.
The upswing in sales of recorded music followed a three-year slump marked by costly litigation, rampant piracy and consolidation among the major labels.
The year’s best-selling albums came from a diverse range of acts, led by pop singer Usher, whose album “Confessions” spent nine weeks at the top of the charts and sold nearly 8 million copies, according to the retail tracking service.
Rounding out the top five were jazz/pop vocalist Norah Jones, rap artist Eminem and country artists Kenny Chesney and Gretchen Wilson. By comparison, the best-selling live music tours last year were by veteran performers like Prince, Madonna and Celine Dion.
U.S. album sales for the 52-week period ended Jan. 2, 2005, totaled 666.7 million units, up 1.6 percent from 656.2 million the year before, Nielsen SoundScan said. Sales of the CD format alone, accounting for 98 percent of the total, rose 2.3 percent compared to 2003.
Moreover, CD sales grew despite a quantum leap in sales of music downloaded from the Internet during the past year — more than 140 million digital tracks in all — a figure roughly equivalent to 14 million albums.
Downloads of whole albums in 2004 topped 5.5 million copies.
For the second half of the year alone, SoundScan reported downloads of 91.4 million singles, well over three times the 19.2 million digital tracks sold in the same period of 2003.
And for the final sales week of 2004, digital downloads hit a record 6.7 million tracks, a massive increase from the weekly average of 300,000 counted by SoundScan when it first began tracking Internet sales in mid-2003.
Rock band Hoobastank led the pack for online song sales, with nearly 380,000 downloads of its hit single “The Reason” last year, followed by Maroon 5’s “This Love” and the Black Eyed Peas’ “Let’s Get It Started..”
In terms of album sales, SoundScan said the musical genres showing the hottest year-to-year growth in 2004 were Latin and country, each posting double-digit increases.
Among the major record labels, Universal Music, a unit of Vivendi Universal remained No. 1 in market share, accounting for nearly 30 percent of total album sales in 2004.
The growth in music sales contrasted with a lackluster year for the live touring industry, which saw a decline of nearly 3 percent in the number of tickets purchased in 2004 as the average price of concert seats rose 3.5 percent to top $52, according to trade publication Pollstar.