The news last week that veteran band Tom Petty and the Heartbreakers scored its first No. 1 album—yes, ever—prompted a number of reactions, ranging from “Petty’s still got it…classic rock rules!” to “Man, it’s way too easy to top the charts these days.”

Both reactions are understandable, but the truth lies somewhere in between. Supporting the more cynical view of Petty’s achievement is Billboard’s disclosure that a large chunk of the Heartbreakers’ 131,000 in first-week sales were fueled by a Live Nation promotion that bundled copies of new album Hypnotic Eye with purchases of tickets to the band’s current tour. (How large? HITS claims it was roughly half of the 131K.) Live-plus-CD bundles have been chart aberrations before—a Prince giveaway in 2004 prompted complaining, and a Madonna live/CD bundle in 2012 both helped and hurt her chart performance—but Billboard and SoundScan now have rules in place to account for the bundling tactic. Petty’s concertgoers paid a surcharge for his CD and were given the choice not to buy it, so those sales count.

However this album got to No. 1, what’s more interesting to me about the triumph by Petty and longtime bandmates Mike Campbell, Benmont Tench et al.—average age: 63—is it’s the second topper on the Billboard 200 album chart in under a month by a middle-aged act, improbably scoring its first No. 1. Hypnotic Eye comes just two weeks after 54-year-old “Weird Al” Yankovic’s Mandatory Fun, which delighted America by ringing the bell in late July.

Tom and Al stand out in 2014, a year in which the No. 1 spot has been monopolized by youthful stuff ranging from Lana Del Ray to Ed Sheeran to the Frozen soundtrack. But taking a wider view, Petty and Yankovic are in good company—they continue an intermittent but persistent, decade-long string of fiftysomething-or-older chart-toppers: acts either reaching the penthouse for the first time, like Neil Diamond or Black Sabbath; or for the first time in decades, like Bob Dylan or Rod Stewart.

These aging acts, who defy the charts’ reification of youth, resist easy categorization or examination. Normally, when chart analysts like me describe a shift in trends, we refer to the epochal switch Billboard made in 1991, when Nielsen SoundScan data was baked into its charts and changed everything we know about how hit records are made. This is not one of those cases. While SoundScan did make it easier for acts of any age to debut at No. 1, in most instances those debuts were by artists under 40—right through the end of the 1990s, youth still ruled on the Billboard 200. (The age question isn’t worth exploring before SoundScan, either—when John Fogerty made “comeback” headlines in 1985 by topping the chart with Centerfield, he was a ripe old 39.)

In the ’90s, the first decade of the SoundScan era, I count just a handful of aging acts who made a chart-topping debut. And—if this 42-year-old does say so himself—they weren’t all that old: Natalie Cole topping the chart in 1991 with her Grammy-bait tribute to dad Unforgettable…with Love, at age 41; Aerosmith ringing the bell in 1993 with Get a Grip, its members’ ages averaging a still-spry 42; Meat Loaf later that same year with Bat Out of Hell II: Back into Hell, at a still lung-busting 46. Even the most celebrated oldster blockbuster of the premillennial era, Santana’s Supernatural in 1999, did so when Carlos was a barely AARP-eligible 52 (younger than Weird Al now!), and it wasn’t his first No. 1 album—just his first in 29 years.