LONDON — Here's a pop-trivia quiz for you.
Hum a track from the latest Paul McCartney album. Now name a Rolling Stones tune from the past five years. When's the next Pink Floyd disc coming out? (Clue: There isn't one.) What was the last Eric Clapton studio album called?
That's right: It's tough. The great old names of British rock haven't exactly been bursting with new material in recent years. There are still tours, of course, and plenty of live albums and "best-of" compilations.
But fresh tunes are thin on the ground. "There isn't much output nowadays, and when there is, it is not always brilliant," says Sheila Whiteley, author of "Too Much Too Young: Popular Music, Age, and Gender."
So have Britain's rock dinosaurs produced their last roar? Are they, to coin a well-worn phrase, too young to die but too old to rock 'n' roll? A strange coincidence last week might suggest not. Two elder statesmen of British dad rock, Sting and Elvis Costello, released albums of new material on the same day.
And yet these new albums encapsulated the problem for the old guard. Reviews were lukewarm. Some critics did find nice things to say about Sting's "Sacred Love" but Costello's "North" was dismissed as "total agony" by one reviewer. So if no one likes your new stuff and fans only want to hear the oldies, why bother recording new tracks?
"There is already this huge appetite for the back catalog, so it's hardly surprising they don't have the drive to compete with the young guns any more," says rock critic and author Neil McCormick.
"Rock music is a young medium," he adds. "When you look at the most creative period, it's before they're 28. An explosion of creativity goes on in the post-adolescent phase. It's hard for them to mine that same creativity later."
Recent discographies often owe more to the marketing man's talent for repackaging old material than to any new creative impulses.
If you hear a Rolling Stones tune on the radio, it's still more likely to be the classic "Jumpin' Jack Flash" than "Anybody Seen My Baby?" from 1997.
"What you seem to get is a celebration of past glories," says Ms. Whiteley, who is also chair of popular music studies at the University of Salford in Manchester. "The fans want a reconfirmation of their youth. It's the oldies that they associate the groups with, and they are the ones they want to hear."
Britain is much less forgiving than America, where "mature" acts like Bob Dylan and Bruce Springsteen have produced acclaimed albums recently. In Britain, Mr. McCormick says, ideas such as sound, subculture, and sonic invention are the driving force, making it difficult for yesterday's men to sound relevant.
But don't ever suggest that to the "aging rocker" himself. David Bowie insists that every new album is his best for decades. Bowie is one of the most prolific rock daddies, producing four albums in the past six years. His new recording "Reality," has received some glowing reviews, along with a few middle-of-the-road write-ups. Sir Elton John believes his 2002 record "Songs from the West Coast" was on par with his 1970s classics. As for the Rolling Stones, the entourage gets extremely touchy if you suggest that their creative juices may be drying up.
"They are going into the studio to record another album," says publicity chief Bernard Doherty. "They do make records, they will make records, they are not hanging up their boots on either the touring or recording front," he says.
All of which makes rock a rather unique art form. You don't hear commentators calling for all painters or all writers or all architects to take enforced early retirement. Even other musical genres are more forgiving. Jazz and blues audiences nurture their legends, many of whom remain productive into old age.
The elders of rock have two formidable hurdles to overcome. The first is burnout. "It's an energetic thing, rock," muses Whiteley, and few legends would disagree: Bowie admitted recently that he had a hard time remembering his song lyrics. Illness forced McCartney and the Rolling Stones to cancel gigs earlier this summer.
The second factor is image, that elusive commodity that may explain why so many acts fade away, according to Dr. Roger Fagge, a lecturer in history, culture, and society at the University of Warwick.
He says that British rock in particular is as much about defying the establishment as it is about the music. And rebellion is hard to preach if, like Sir Paul, Sir Mick, or Sir Elton, you have a knighthood and a stately home and a few million in the bank.
"When rock first appears with Elvis, he was a rebel image in the 1950s, sexually exciting, and represented a rebellion against that middle-aged mainstream conformity, and that's always been an important part of rock," says Dr. Fagge.
"So now you have to ask: When you're 17 or 18, do you want to watch some 50-year-old with a beer belly, or some young figure with an attitude?"
But it's not just the grand old men of rock who are up against it. The majority of so-called New Romantics, who minced and mimed so expertly in the 1980s, have disappeared without trace, though Duran Duran is plotting another comeback.
Even 1990s Britpop acts are starting to look worn and jaded. Blur and Radiohead have had to reinvent themselves to stay relevant. Blur has experimented with world music, and Radiohead is weaving in more electronic sounds compared to 10 years ago.
"Hope I die before I get old," sang Roger Daltry of The Who in a 1966 anthem to youth and rebellion.
Yet in a way they were talking about every generation. In a world as ephemeral as rock music, the only artist immune to the career-threatening aging process is he who dies young.
So have we heard the last of the British dinosaurs of rock?
Will we still need them, will we still feed them, when they're 64?
Rock critic McCormick thinks so.
"Age is becoming more subjective now in pop culture, because pop culture itself is over 50 years old," he says. "I still think there'll be great work to come from these people."