Despite their length, both feel more like snacks than fully satisfying meals. That’s not such a problem with “100 Greatest Songs” — it doesn’t really pretend to be anything other than junk food — but “The 7 Ages of Rock,” which originally aired on the BBC and is narrated by Dennis Hopper, bears the weight of importance. So its sins are more glaring. Now, if it had been titled “The 7 Ages of British Rock,” the series’ Anglophilic focus would be more understandable.

But, as it is, it’s just myopic. The first episode, “My Generation: The Birth of Rock,” kicks off in 1965 with the Beatles, the Stones, the Who and the Animals, and it claims this was the first age of rock. While the debt these bands owed to American blues is acknowledged, totally overlooked are those performers who provided the bridge between the blues and the Beatles: Little Richard, Jerry Lee Lewis, Bo Diddley and even Elvis Presley.

The producers might claim that these artists are “rock ‘n’ roll,” not “rock” as it came to be known in the late ’60s, when the music became less obviously blues-based. Still, “The 7 Ages of Rock” does a disservice to those whose pop musical history may be hazy. The same is true for the fifth episode (”We Are the Champions: Stadium Rock”), in which the Brits — Queen, the Police, Dire Straits, Live Aid, U2 — get much of the glory.

Bruce Springsteen and Kiss also get time but there’s little to no exposure for many of the major American acts of the day — cough, Grateful Dead, cough — who could fill festivals and stadiums. Americans should be more prominent in Episode 6 ( “Left of the Dial: Alternative Rock 1980-1994″) — presumably Nirvana will be a major presence — but it was not sent for review. But then the final episode, “Indie,” is completely dedicated to U.K. bands from the past 15 years.