Rapper 2 Chainz' debut studio album, "Based on a T.R.U. Story," bows at No. 1 on the Billboard 200, selling 147,000 copies, according to Nielsen SoundScan. That's a slightly more robust figure than had initially been projected last week. Some industry sources were thinking the set would sell between 130,000 and 140,000.

2 Chainz is the third act this year to start at No. 1 with a debut studio effort, following One Direction's "Up All Night" (on the March 31 chart) and Jack White's solo bow "Blunderbuss" (May 12). The last hip-hop act to start at No. 1 with such a set was on Nov. 26, 2011, when Mac Miller's "Blue Slide Park" opened in the penthouse (144,000).

Though "Based on a T.R.U. Story" is 2 Chainz' debut studio album, he's already notched 10 hit singles on the Hot R&B/Hip-Hop Songs chart since first arriving in 2011. He initially dented the tally in early 2011 as Tity Boi, before switching to 2 Chainz later that year.

When a debut isn't a debut: Though 2 Chainz' "Based on a T.R.U. Story" is his debut studio album, one could argue that with all of his mixtapes, he's not actually a debut act. And we can't forget how he was half of the Playaz Circle duo, which charted a pair of albums on the Billboard 200, one of which reached No. 3 on Top R&B/Hip-Hop Albums in 2007 ("Supply & Demand"). So, in a way, 2 Chainz is more like Jack White, in that he's been a presence on the chart in some form, and has been active in the industry, but didn't release a proper solo studio debut until this year. While White's "Blunderbuss" was his first solo set, it followed his chart success as part of groups the White Stripes, the Raconteurs and the Dead Weather.

So, what was the last true debut act to start at No. 1 with his or her first album?

Well, One Direction counts-to a degree. Yes, "Up All Night" was the U.K. "X Factor" group's first album (no mixtapes for those boys). But, much like U.S. "American Idol" contestants, One Direction had months of exposure and incubation on TV before its debut arrived. The five-piece came together on the 2010 edition of "The X Factor," competed on the series until it finished in third place, then continued to build momentum until the bow of its first U.K. album in late 2011. By the time of the act's stateside arrival in early 2012, its core fan base was already energized thanks to social media. So, while "Up All Night" was indeed a debut, the group itself wasn't a complete unknown.

But then what about Mac Miller's "Blue Slide Park?" The Rostrum Records set was his first studio effort, but it followed many mixtapes during the course of at least four years. OK, then maybe Scotty McCreery's "Clear As Day" on Oct. 22, 2011? Again, there's the "American Idol" factor... J. Cole with "Cole World: The Sideline Story" on Oct. 15, 2011? Again: Mixtapes and a lot of guest turns on others' work preceded "Cole World." Scrolling back farther, we could kick out "Bad Meets Evil's Hell: The Sequel" (No. 1 debut on July 2, 2011) since it's less of a new act and more of a super-duo (Eminem and Royce Da 5'9").

The last true debut artist to see his or her debut album bow at No. 1? Though we could argue this for an entire column or two, perhaps it's Ke$ha, who launched atop the list with "Animal" on Jan. 23, 2010, after having released only one single under her own name: the album's lead track, "TiK ToK."

20 at 10 million: Linkin Park's "Hybrid Theory" becomes the latest release to join the 10 million-sellers club, as it crosses the threshold this week.

The band's debut album, released in 2000, becomes the 20th set to sell 10 million since Nielsen SoundScan began tracking sales in 1991. Earlier this year, Usher's Confessions hit the mark as well. Since 1991, the highest-selling album (according to SoundScan) is Metallica's self-titled 1991 release, which has moved 15.8 million. Shania Twain's "Come On Over" is second with 15.5 million, and Alanis Morissette's "Jagged Little Pill" is third with 14.8 million.

"Hybrid Theory" is also one of only four 10 million-sellers that didn't reach No. 1 on the Billboard 200. It peaked at No. 2 on the tally, after initially bowing at No. 16. Twain's Come On Over halted at No. 2, while Bob Marley & the Wailers' "Legend" (11.1 million) reaches a new peak of No. 18 this week and Backstreet Boys' self-titled debut (10.1 million) hit No. 4.

Don't cry for Linkin Park's No. 2 plateau, though: "Hybrid Theory" was the No. 1-selling album of 2001 in the United States with 4.8 million sold. Since then, the band has notched five No. 1 albums, including its most recent effort, this year's "Living Things."