Some of today's biggest classic rockers got their starts years ago. Let's take a look at some of them today, starting with Paul McCartney, who is turning 72 on June 18, 2014. He's seen here at a charity event in Santa Monica, California, on Sept. 25, 2013.
McCartney is seen here (second from left) with the rest of the Beatles waving to fans after arriving at Kennedy Airport in February 1964 at the height of Beatlemania. McCartney was 21 years old at the time.
Rod Stewart is seen here in London on May 19, 2013, during a toast to announce a concert tour supporting his "Time" album.
Stewart, seen here in November 1976, first became famous as a member of the Jeff Beck Group and Faces before finding solo success in the 1970s. Some of Stewart's best known songs include "Maggie May," "Reason to Believe," "Every Picture Tells a Story," "You Wear it Well," "Hot Legs," "Da Ya Think I'm Sexy?," "Young Turks" and "Downtown Train."
Led Zeppelin guitarist Jimmy Page, who turned 70 on Jan. 9, 2014, is seen here on Oct. 12, 2012, arriving for the U.K. premiere of "Celebration Day," a documentary of Led Zeppelin's 2007 concert at London's O2 Arena.
Page, second from right, is seen here with the rest of Led Zeppelin in an early promotional photo from the late 1960s.
After years of silence, David Bowie, who turned 67 on Jan. 8, 2014, popped back on the music scene in a big way in 2013, releasing "The Next Day," his first album in nearly a decade in March 2013. He still remains partially retired and has not toured since 2004 and has not performed live since 2006.
Bowie's seen here on the cover for the 1972 reissue of his 1969 "Space Oddity" album.
Former Pink Floyd frontman Roger Waters, who turned 70 on Sept. 6, 2013, is seen here on Nov. 12, 2012, performing during the "12-12-12" benefit concert for victims of Superstorm Sandy.
Waters (second from left) is seen here in the early 1970s with the rest of Pink Floyd. The rest of the band includes (from left to right) Rick Wright, Nick Mason and David Gilmour.
Bruce Springsteen is still "The Boss" 40 years into a career that shows no sign of stopping.
Bruce Springsteen after he had just released his "Born In The U.S.A." album in 1984. He burst onto the scene in 1973.
Former Beatles drummer Ringo Starr is still bringing peace to music lovers through his All Starr Band tours.
Ringo Starr in his 20s with a classic '60s hairdo.
Alice Cooper today. He is still performing, but he also likes to spend his time on the golf course.
Back in the days when Cooper would perform with a boa constrictor.
Billy Joel today. He is still twinkling the ivories for his fans, and often times face-face with another Piano Man, Elton John.
Joel -- shown here in his late 20s -- still had a full head of hair when he started producing hits in the early 1970s.
Today, Elton John is as big as ever, and tours solo and often duets with fellow Piano Man Billy Joel.
John's first album debuted in 1969 and he hit his stride in the 1970s with such smash albums as "Goodbye Yellowbrick Road," "Captain Fantastic and the Brown Dirt Cowboy" and "Rock of the Westies."
Eddie Van Halen is all grown up and still tours with Van Halen -- along with his bassist son, Wolfgang (his child with Valerie Bertenelli).
Eddie Van Halen in his younger days. The band got its start in the 1970s, with its self-titled debut album coming out in 1978.
Today, Pat Benatar still performs her hits, "Heartbreaker" and "Love is a Battlefield," when on tour with her guitarist husband, Neil Giraldo.
In her late 20s, Benatar was one of the top female rockers of the 1980s, but she got her start in 1972 and had her first big hit in 1979 with "Heartbreaker."
Ozzy Osbourne today, still playing metal shows for the fans of his solo work and songs as the lead singer of Black Sabbath.
Speaking of Sabbath, here's Osbourne (second from left) in his younger days, leading up Black Sabbath's original lineup in the 1970s.
The Rolling Stones -- Mick Jagger, Ronnie Wood, Charlie Watts and Keith Richards -- continue to rock out after 50 years.
The Rolling Stones, known for their bad boy image, sure look pretty wholesome back in the old days.
Since his first stint with Van Halen came to a close in 1985, David Lee Roth has rejoined the band several times over the years, including in 2012 for their most recent concert tour and their first new album in 14 years.
Roth started out with the original lineup of Van Halen back in the 1970s, when he was known for his outrageous sense of style and flair.
Tina Turner, now in her 70s, has still got it!
Turner in the 1960s with her ex-husband and collaborator Ike Turner.
Roger Daltrey today. The Who singer joined guitarist Pete Townshend for a performance at Super Bowl XLIV in 2010 and toured in 2012 playing the album "Quadrophenia."
A younger Roger Daltrey shown here before he adopted the famous curly, blond locks.
In 1984, Gene Simmons, in his mid-thirties, was still experiencing the popularity of his heavy metal band Kiss, which rose to fame in the mid-1970s.
Gene Simmons today, sans the make-up and costumes he wears as "The Demon" in the rock band Kiss.
Thousands of pro-democracy protesters are camped out on major highways in the heart of Hong Kong, defying government attempts to both coerce and cajole them into giving up their extraordinary demonstration.