Ever since the breakup of The Beatles, fans had been clamoring EMI to open the vaults. The record company insisted that there was nothing worth releasing. This was proven wrong (sort of) in the early '90's when the Unurpassed Masters bootleg CD series appeared.
The remaining band members responded with a 10 hour documentary and 6 CD's worth of previously unreleased material. To sweeten the deal, the remaining band members took two unfinished Lennon songs and finished them.
Those two songs were included on The Beatles Anthology and also released as 45's with B-Sides that were not included on the massive set.
I can't let mention of The Beatles Anthology CD's go without my humble opinion getting in the way. In reality, there is only an album's worth of good material here. This works out to be only 12% of what ended up being released. The bulk of the rest consists of ideas that were scrapped in favor of the final release, some low-fi live tracks, and the worst of all 'outfakes.' An 'outfake' is a blending of several tracks to come up with a unique version. An extra instrumentation from this track. A scrapped vocal added this other track, etc. Take, for example, And Your Bird Can Sing. Giving us a vocal track where the band descends into laughter is fun, but a bit tacky to manufacture.
With all this, where are some of the rumored tracks? The 25 minute Helter Skelter? The I Want You (She's So Heavy) with a McCartney vocal? It's All Too Much with the extra verse as heard in 'Yellow Submarine?' The rooftop concert complete and unedited? They may be out there, but they may not be that good.
Bottom line - The Beatles Anthology took 6 CD's to drive home the point that The Beatles made the correct artistic decisions the first time around. There's a reason they scrapped those ideas in the first place.
Here are the 45's
Free As a Bird b/w Christmas Time is Here Again
Lennon demo completed by the other Beatles with production by Jeff Lynne. The B-Side is a Christmas ditty originally part of one of the yearly records mailed to the fan club. Personally, I would include this on the (imagined) single LP version of Anthology. It didn't even make it to the massive set.
Real Love b/w Baby's in Black
Another Lennon demo finished by the others. B-Side is from the Hollywood Bowl concerts - which was released on vinyl and has not yet seen the light of day digitally.
You may think that George, John and (especially) Ringo are flashing gang signals or signaling the pitcher, but in reality they were holding cigarettes. Someone airbrushed them out to make the photo safe for today's consumer.