For the second time since SoundScan started counting downloads in 2003, track sales suffered a sales decline, something that occurred in the first three quarters of 2010. So far this year, track sales are down 1.3% as of March 31, according to Nielsen SoundScan.

This year, industry executives attribute the decline to a lack of hits. Last time in 2010, they blamed LimeWire. But after the peer-to-peer site was shutdown, track sales rallied and closed out the year with a 1.1% increase.

In 2013, only 15 songs have reached the 1 million unit milestone so far, while last year 21 songs accomplished that feat. But this year’s best selling song download, Macklemore and Ryan Lewis’ “Thrift Shop,” has scanned almost 4.2 million units. Last year’s best selling title for the first quarter was Fun.’s “We Are Young” (featuring Janelle Monae), which scanned 2.75 million units.

Against that, album sales totaled 74 million during the first quarter, down from 77.8 million units, a drop of 4.9%. Within that, CD sales were down 15.4% to 40 million from 47.4 million in the first quarter of 2012; digital album sales increased 10.4% to 32.4 million units, up from 29.4 million units.

With nearly 1.3 million in scans, Justin Timberlake’s new album, “The 20/20 Experience,” is the top selling album this year, as well as the top selling digital album with 558,000 downloads.

Overall, albums (plus track equivalent ones whereby 10 tracks equal one album) dropped 3.8% to 109.7 million units, down from 114 million units in the first quarter of 2012.

Moving over to market share, the Universal Music Group remains the dominant player, raking up 37% for album plus track equivalent market share now that it has absorbed EMI, versus the 30.1% in album plus TEA it had last year before it acquired EMI.

Looking at genre sales, rock was the sole large category to enjoy an increase in sales, growing to 26.1 million units from 25.4 million units in 2012’s first quarter, an increase of 2.6%. Country was down less than 1%. But the other large genres like gospel, R&B/Hip-hop, Latin and electronica posted declines greater than the industry downturn in album sales so far this year.

Finally, in tracking where the consumer is shopping, chains suffered a 19.7% decline in the first quarter with album sales falling to 9.9 million units from 12.3 million units. Scans at mass merchants dropped 17.7% to 18.7 million units from 22.8 million units; and independent stores saw album unit sales fall to 4.6 million units from 5.2 million units, a 13.1% decline.

Consumer are clearly migrating to the web, as digital album sales jumped 10.4% to 32.5 million units from 29.4 million copies; and online CD sales increased 2.3% to 8.4 million units from 8.1 million units. [Billboard.biz]