One-named acts rule 2012 so far: Half-way through the year, Adele and Gotye have bragging rights to the top-selling album and single so far.

Adele’s “21” has some more than 1 million copies this year, while Gotye’s “Somebody That I Used To Know,” which topped the Billboard Hot 100  for several weeks, is the top selling single, moving 5.5 million downloads.

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The top selling album released in 2012 belongs to Lionel Richie. His “Tuskegee,” a collection of remakes of his hits with country artists, has sold 912,000, according to Billboard.  At the mid-way point, 11 albums have moved more than 500,000 units this year. That is a substantial drop from the 16 that achieved that mark this time a year ago.

Rounding out the top five album sellers in 2012 so far followed “21” and “Tuskegee” are One Direction’s “Up All Night” (899,000), Whitney Houston’s “Whitney: The Greatest Hits” (818,000) and “Now That’s What I Call Music 41” (714,000).

In addition to “Somebody That I Used To Know,” other top single sellers include fun.’s “We Are Young” featuring Janelle Monae (5.05 million) and Carly Rae Jepsen’s “Call Me Maybe” (4.06 million).

Overall, as the number of albums surpassing the 500,000 mark indicates, album sales are down 3.2% year-to-date, according to Nielsen Soundscan. That bad news comes after last year saw album sales increase 1.4% —the first mid-year increase since 2004. While album sales are down, digital track sales are up 6% over this time last year.