December 11, 2009

By By Billboard staff

Most of the decade-end music tallies in this special online section represent aggregated sales or radio airplay (audience impressions or total plays) for each artist and title from the weekly charts on which they appeared from the start of the 2000 chart year (Dec. 4, 1999 charts) though the end of the 2009 chart year (Nov. 28, 2009 charts).

The sales totals are based on data compiled by Nielsen SoundScan, with radio airplay measured by Nielsen BDS.

Sales or airplay registered before or after a title's chart run are not considered in the Billboard decade-end standings. That detail accounts for some of the differences between these lists and the decade-end recaps that are compiled independently by either SoundScan or BDS.

Because of changes in Billboard chart methodology during the decade, some ranking are based on a point system, instead of aggregated sales or airplay compiled during a chart run. All recaps for the Hot 100, R&B Songs, Country Songs, Gospel Songs, Christian Songs, Christian AC and the four Latin sub-genre radio charts (Regional Mexican, Pop, Tropical and Triple A) utilize an inverse point system, with weeks at No. 1 earning the greatest value and weeks at the lower end of the chart earning the least. This explains why some songs might be ranked in a different order than they appear in their corresponding year-end rankings.

The top artists of the decade category is based on a formula blending sales point totals from the Billboard 200 recap and recap points from the Hot 100. The top overall artists category for Latin, Country and R&B were determined by employing an inverse point system based on an artist?s weekly ranking on each format?s respective albums and songs charts.

CLICK HERE FOR THE DECADE-END CHARTS

CLICK HERE FOR THE YEAR-END CHARTS

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