Although overall U.S. music sales were up in 2008 -- with more than 1.5 billion albums, singles, music videos and digital tracks sold -- album sales alone dropped an average of 14 percent across all recorded musical formats.

Sales of country music albums plunged from 62,696,000 units in 2007 to 46,657,000 in 2008, a drop of 24 percent, according to Nielsen SoundScan, the company that monitors actual retail purchases of music.

But there was good news for country as well. Taylor Swift was the best-selling album artist in all popular music formats with 4,003,000 copies sold. Sugarland ranked eighth by selling 2,063,000.

Lil Wayne's Tha Carter III was the single best-selling album of the year, moving 2,874,000 pieces across the scanner.

The Nielsen SoundScan totals cover sales made between Dec. 31, 2007, and Dec. 28, 2008.

Sales of physical albums slumped significantly in every format. Alternative rock dipped from 88,604,000 to 80,919,000; Christian/gospel from 34,017,000 to 29,793,000; classical from 18,044,000 to 13,323,000; jazz from 14,047,000 to 11,791,000; Latin from 31,853,000 to 25,125,000; metal from 52,951,000 to 50,476,000; new age from 3,210,000 to 2,943,000; rhythm & blues from 95,555,000 to 77,014,000; rap from 41,662,000 to 33,410,000; rock from 149,414,000 to 139,666,000; and soundtracks from 24,570,000 to 20,847,000.

Swift had two of the Top 10 best-selling albums: Fearless, which ranked No. 3, on sales of 2,112,000 copies, and Taylor Swift, at No. 6, which sold 1,597,000 units during its second year on the charts. (Sales of Beautiful Eyes, Swift's CD/DVD package available exclusively through Walmart, rounded out her grand total.)

Swift ranked No. 2 among the Top 10 best-selling digital artists with 8,793,000 digital tracks sold. In this category, she outpaced Kanye West, Chris Brown, Britney Spears, the Jonas Brothers, Coldplay, Katy Perry, Leona Lewis and Jordin Sparks. Only Rihanna exceeded her.

In addition, Swift's Fearless was the No. 5 best-selling digital album, racking up a total of 225,000 units. It was also the No. 4 best-selling collection via Internet orders with 82,000 copies shipped.

Five country performers are among the Top 10 best-selling artists of the "SoundScan Era," a period that began in 1991 when that monitoring technology was introduced. Garth Brooks stands at No. 1, with 68,143,000 albums sold. George Strait is No. 6 (40,619,000); Tim McGraw No. 7 (37,591,000); Alan Jackson No. 8 (36,520,000); and Shania Twain No. 10 (33,707,000).

Twain's Come On Over is the best-selling album of the SoundScan Era. It now boasts 15,473,000 copies sold.

Nielsen Broadcast Data System, which monitors radio airplay, reported six country artists among the 10 acts getting the most airplay. They are Rascal Flatts (No. 2), Toby Keith (No. 3), George Strait (No. 5), Tim McGraw (No. 6), Taylor Swift (No. 8) and Alan Jackson (No. 9).

No country songs made it into the Top 10 most popular ringtones last year.