Shawn Mendes

Shawn Mendes photographed by Blossom Berkofsky on July 9, 2014 at Industria in New York.

Blossom Berkofsky

This week on the Billboard 200 albums chart, Tom Petty and the Heartbreakers finally claimed its first No. 1 album, as Hypnotic Eye bowed in the top slot, selling 131,000 copies in the week ending Aug. 3, according to Nielsen SoundScan.

Of course, aside from Petty there was -- as usual -- lots of chart action. Let's take a closer look at the rest of the chart:

-- Shawn Mendes, The Shawn Mendes EP - No. 5 - Vine star-turned-major-label singer Shawn Mendes arrives at No. 5 with his self-titled debut EP, selling 48,000 in the week ending Aug. 3, according to Nielsen SoundScan. The Island Records effort is the fourth EP to hit the top 10 this year, following earlier short sets from 5 Seconds of Summer, Luke Bryan and Austin Mahone.

A year ago at this point, no EPs had reached the top 10, though four made the region by the close of 2013.

The shorter album — generally defined as containing between four and eight songs — has gained in popularity in recent years. 

In 2013, the Billboard 200 saw 82 EPs debut on the chart — 7.2% of the 1142 titles that debuted in total. That was up tremendously from 10 years earlier, when just 18 EPs hit the chart in 2003 (2.2% of the 802 total debuts).

EPs are an economical way to introduce a new artist, and can also be used as a stopgap between full-length sets by established stars. 5 Seconds of Summer's top 10 set She Looks So Perfect EP, for example, preceded its No. 1 self-titled full-length debut.

-- 'N Sync, The Essential 'N Sync - No. 25 - The pop group tallies the fourth top 25-charting album for Sony Legacy's Essential series, following Bruce Springsteen (No. 14, 2003), Barbra Streisand (No. 15, 2002) and Billy Joel (No. 15, 2013). The Essential 'N Sync sold 10,000 copies in the week ending Aug. 3. The Essential-branded greatest hits series launched in 2001 and has released more than 100 titles. Sony Music says it is their most successful product line, and it has sold 22 million in the U.S., according to SoundScan. The Essential albums often enhance an artist's existing catalog of product, which usually already includes a previously-released greatest hits collection. 'N Sync's 34-track Essential title, for example, follows the group's 12-song Greatest Hits, released in 2005. 

-- The Allman Brothers Band, The 1971 Fillmore East Recordings - No. 57 – The veteran act claims its 27th chart entry, and second this year, following Play All Night: Live at the Beacon Theatre 1992 (No. 43, March 8). The group hasn't debuted two albums on the chart in a year since 1981.

-- Cher, Closer to the Truth - No. 70 - The album once again re-enters the chart (4,000; up 125 percent), thanks to sales generated by redemptions of the album bundled with tickets to Cher's current tour. Those that purchased tickets to the tour also had the option to receive her album as part of the purchase price. Only albums that were redeemed by the consumer count as sales toward Billboard's charts. (Many ticket buyers decline the album.)The out-of-nowhere jump was spurred by an email blast to customers, reminding them of the album offer.

-- James Brown, 20 All-Time Greatest Hits! - No. 133 - Though this 1991 album has sold 1.5 million copies, this is its first week on the Billboard 200. Why is the album only finally debuting this week? Back in the early 1990s, when the set was chart-eligible, it never sold enough in a single week to reach the list. After two years, the album was no longer eligible to chart on the Billboard 200, but instead shifted over to the Top Catalog Albums chart (where it charted for 10 weeks). The Catalog chart is for older albums, generally defined as those two years old, or older. So, if 20 All-Time Greatest Hits! Is considered a catalog album, why can it now chart on the Billboard 200? At the end of 2009, the Billboard 200 began allowing catalog titles to chart again, thus, the Brown title can finally debut on the list. It's one of two debuts for Brown this week, joined by his soundtrack to the new film about his life, Get On Up (No. 63).

-- Jon Batiste and Stay Human, Social Music - No. 134 - The album debuts at No. 134 and also re-enters at No. 1 on Traditional Jazz Albums (its first week at the top) following Batiste's interview and performance on "The Colbert Report" (July 29). The album sold 3,000 in the week ending Aug. 3, up 10,400 percent.

-- Gaelic Storm, Full Irish: Best of Gaelic Storm — 2004-2014 - No. 169 - On World Albums, the band collects its fifth No. 1 with this new set. Only four acts have claimed more leaders: The Chieftains (seven), Gipsy Kings (eight), Celtic Thunder (10) and Celtic Woman (10).