Muse moves in at No. 2 on the Billboard 200 with its highest-charting album, "The 2nd Law", selling 102,000 copies in its first week, according to Nielsen SoundScan. However, it's not enough to bump Mumford & Sons' "Babel" out of the top slot, as the set (169,000; down 72%) becomes the first since June to rack successive weeks at No. 1.

TV classics: One-time "America's Got Talent" runner-up Jackie Evancho arrives at No. 7 on the Billboard 200 with her latest effort, "Songs From the Silver Screen" (41,000 sold). It's the 12-year-old's fifth entry on the tally and marks her third top 10 effort.

The common thread running through all of Evancho's albums is that they're basically cover sets. She first appeared on the chart with the indie release "Prelude to a Dream" in 2010, right as she was performing on TV. The set was recorded when Evancho was 9 years old, and features her takes on such tunes as "The Prayer" and "Amazing Grace." After placing second on "America's Got Talent" in 2010, she signed with Syco/Columbia and issued the four-song Christmas EP "O Holy Night" in November of that year. So far, it has sold 1.1 million. In 2011, she followed the EP with the full-length covers set "Dream With Me" (682,000 sold) and another holiday title, "Heavenly Christmas" (310,000).

The diminishing returns for her albums isn't surprising, and one shouldn't expect the new "Songs From the Silver Screen" to buck the trend. She, like many unconventional acts whose careers launched on TV, are sometimes difficult to market and promote. In turn, she's saddled with the task of recording covers and Christmas tunes in order to capture attention. With limited support from traditional media and radio, the covers route is often the easiest way to get guaranteed sales with a fickle audience. It's easier to sell covers when an artist -- young or old -- can't count on mainstream media to expose, and familiarize the public with, original material.

The real challenge will come when Evancho transitions from child star to teen singer. Will she be able to make the switch? Does she even want to? Will she record original material?

Her career so far might bring to mind that of another big-voiced female singer who got her start in the classical world thanks to TV at a very young age: Charlotte Church.

At 12 years old, Church got her U.S. start in 1999 through PBS concert specials, which fueled sales of her debut album, "Voice of an Angel". It has sold 1.9 million, and was the first of her three million-selling albums. Most of those releases consisted of Church interpreting familiar classical pieces and older hit songs, along with holiday favorites.

In 2005, Church released her first album of original pop material, "Tissues and Issues", which peaked at No. 5 on the Official U.K. Albums chart. While the set wasn't released in America, it spun off four top 40 singles in the United Kingdom, including the No. 2 smash "Crazy Chick." Since then, however, the singer departed Sony Music in 2006 and intermittently released independent music projects. She most recently issued the four-song pop EP "One in September", in America and elsewhere.

Evancho might also remind one of her fellow "America's Got Talent" franchise star: Susan Boyle. The singer, who is also Evancho's Syco/Columbia labelmate, was a runner-up on the U.K. edition of the show and is prepping the release of her fourth album in as many years, S"tanding Ovation: The Greatest Songs From the Stage". Like the bulk of Boyle's releases, it's a covers effort and features popular favorites from Broadway musicals.

ch-ch-changes: As mentioned, some long-standing charts have undergone a major methodology overhaul. Hot Country Songs, Hot R&B/Hip-Hop Songs, Hot Latin Songs, Hot Rock Songs and Rap Songs are now employing the same formula as the Billboard Hot 100, causing some dramatic chart movements among some titles compared with their ranking under the lists' prior methodologies. Besides the one-week chart-rank shuffle associated with the change, there's one other housekeeping item worth noting. While the songs on the genre charts should now rank in order of their respective placement on the Hot 100, there may be some exceptions. Each genre chart will operate under its own recurrent rules with descending titles below No. 25 being removed after 20 weeks on the chart, regardless of their Hot 100 statuses. Titles on the new 25-position R&B Songs and the revamped Rap Songs will move to recurrent when they do so on Hot R&B/Hip-Hop Songs. For the first week under the new formula, titles that were recurrent on a genre chart prior to this week were removed.