First, the first time you hear a song you probably think it's new and original. That's how old songs become popular again. And you'll identify that version of that song with the time you heard it.
Second, the way music is conceived and presented has changed drastically over the years, so saying anything AT ALL about "of all time" is meaningless.
You cite numbers about the Beatles. I happen to agree that they're the greatest rock group of all time, but then there's an emotional attachment: I was a teenager when they burst on the scene and A LOT of their songs remind me of dear times when I was younger, for instance the time that a dozen people got together to listen to the new album, the white album, start to finish, a couple days after it was released.
Nobody does that any more, for many reasons, but that doesn't mean that there won't be better songwriters or musicians than The Beatles. Or that there weren't better ones in the past.
Looking further back, there was a time when few performers wrote their own material. The Beatles "churned out" over 225 songs, right? In a grand total of seven years.
Irving Berlin wrote songs between 1907 and 1966. Wikipedia says he wrote around 1250 songs. His songs include God Bless America Blue Skies Puttin' On The Ritz (remember Young Frankenstein?) White Christmas There's No Business Like Show Business Let's Face The Music and Dance How Deep is the Ocean Let's Have Another Cup of Coffee
Many of those songs were written for Broadway Musicals. Despite their movies, the Beatles can never be said to have created a musical. See, it wasn't the time for that.
And how about George and Ira Gershwin?
I Got Rhythm Lady Be Good Someone to Watch Over Me Fascinatin' Rhythm Embraceable You They Can't Take That Away From Me The Man I Love Let's Call The Whole Thing Off Summertime (Look up Janis Joplin's recording of this!) It Ain't Necessarily So A Foggy Day Somebody Loves Me
George Gershwin also wrote music for which Ira didn't write words. Rhapsody in Blue comes to mind...
And George Gershwin died when he was 39 years old. That would have been 1979 for John Lennon (killed in 1980) and 1982 for McCartney.
So, yes, The Beatles were the best group of all time, but only if you slice up the meaning of "all time" as well as realize that your statement is limited by the fact that you're only talking about rock groups. For music in general, they are titans among other titans, but not the best.
A good answer is easier with a clear question giving the make and model of everything. "The biggest problem in communication is the illusion that it has taken place." -- G. “Bernie” Shaw
