...to many of us. To some of us it was Blonde on Blonde.
According to Wikipedia .....
"The first double album was Benny Goodman's Live at Carnegie Hall, released by Columbia Records in 1950. The first rock double album, and first studio double album was Bob Dylan's Blonde on Blonde in 1966, also on Columbia"
So Bob beat the Beatles to it by a good two years! Zappa, Hendrix, Cream, Donovan, Frank Sinatra, and the Animals (plus several others) also released double LPs before the fabs.
There were some great double LPs before, and lots more after, but I still think the White Album is my favourite double album - if not my favourite album EVER.
It covers a whole range of musical styles and diverse lyrical themes, has some of the greatest Beatles vocals ever recorded, a guest appearance by Clapton, some classic songwriting, swings from 1920s pastiche to late '60s way-out experimentation in the space of a few tracks, goes from solo acoustic songs to full-on orchestral arrangements, etc etc.
And it is packaged like no other album - they were so big they could get away with a plain white album sleeve, with every sleeve individually numbered.
While Sgt Pepper seems to me to be very much of its time, the White Album could be released today and still sound fresh.
An amazing piece of work all round. Doesn't matter that the band was falling apart at the time - in fact, that is part of what makes it great.
I LOVE it!