Local voices from music and music-related fields:

David Fiorenza, instructor of economics, Villanova University: They had a big impact on the way the pop-music industry developed. They were among the first rock acts that was a band, as apart from a single artist, who wrote their own material and played their own instruments. They also had their own, or nearly their own, music publishing companies, which blazed a trail for a lot of artists.

Even if they did not invent them, they established several practices. They did the connect-the-dots tour, scheduling concerts close together instead of crazily zig-zagging between distant towns. They designed a tour much like a political campaign might be designed today. Also, from the beginning in the United States, they were thinking bigger venues. Where Frankie Avalon and Bobby Rydell might play the Steel Pier in Atlantic City, they wanted the Convention Center.

The Four Seasons were successful, but they didn't have the international accent, nor did they have the marketing campaign. Pop-music marketing had seldom been done like that before, in 1964-66. So much merchandise, lunchboxes, magazine covers, an animated TV show, and you could personalize each one, John, Paul, George, and Ringo. Whereas the Seasons had only Frankie Valli, the Beatles marketers could split it, if you wanted, into four markets, by the boy you liked best.

Most of all, they were very adept at handling journalists, and they won a press following by their self-possession and wit at news conferences. They were already very seasoned at that even before they got here. That was part of the marketing, too.

I'm amazed by their cross-generational appeal, how durable it still is. You hear kids in the street, still, today, humming their tunes.

Helen Leicht, radio personality, midday host at WXPN-FM (88.5): I always had my blue transistor radio at my ear because I had to hear every Beatles song whenever it played on WIBG. I tried to win Beatles tickets to the Shea Stadium 1965 show, but I never won them.

When it was announced they were coming to JFK in Philadelphia in 1966, I lived in South Philly, so I walked to Snyder Avenue and bought myself one ticket. Five dollars. I still have the ticket. My mother said I couldn't go alone. I was heartbroken, but then my uncle said we could all go, my mom, my aunt, all of us. We made it to JFK, but we could barely hear the band over the screaming.

Because of my love for the Beatles, I began Breakfast With the Beatles in 1976 on WIOQ, and it has grown and continues.

George Manney, composer, musician, producer, CEO of Geo Sound in Philadelphia (geosound.org): I saw them live three times, and met them individually in the 1970s. They've influenced me on so many levels, as a musician, as a producer and arranger.

In 2012, for Paul McCartney's 70th birthday, a band I'm part of, Charlie Gracie and Clutch Cargo, released a McCartney tune, "Mull of Kintyre," as a benefit for the Philadelphia Police and Fire, Pipes & Drums Band.

At Sam Ash, where I work sometimes, I deal with a lot of younger, up-and-coming artists, and so many are still totally enthralled by them. The Beatles had an outsider's version of American rock, they heard it differently.

Charlie Phillips, musician, recording artist (charliephillips.com): What they gave me was a love of melody, of the finely crafted song, which is what I love about '60s pop, and they laid the groundwork for that. When I was four, I had my head in the stereo speakers listening to Sgt. Pepper's Lonely Hearts Club Band. By now, melody is worked into my brain; it's cellular memory.

And in the studio - and I've recorded three CDs - my love for arrangement and sound-landscapes, that's them, too. Start with a guitar, build a sonic picture with a piano there, a tambourine there. I never want to sound derivative, but there's no question the Beatles are with me in the studio. And finally, the care lavished on every track. Their producer, George Martin, said something I found and pasted to my old four-track recorder: "We didn't stop until we were confident there was no possibility of further improvement." That's my inspiration.