Enhanced "Let It Be"

There are two versions of "Let It Be". One is the Glyn Johns Mix and is available on the Apple 45 single, the "1967-1970" compilation as well as the "Past Masters" compilation. The second version and different Phil Spector mix (with a different guitar solo from George) was commercially released on the Apple LP/CD "Let It Be".
On January 04 1970, with Paul, Linda, George and Ringo present the enhancement of the song was recorded by adding some brass overdubs, some cellos (not heard but "felt" on the second mix). Other overdubs included Paul replacing the first version's bass playing which was originally played by John. Two significant overdubs were also added: Some high backing vocals from Paul, George and Linda (the only time Linda appears singing on a Beatles record) as well as a heavy distorted guitar solo from George replacing the tremolo solo on the first version. Percussion overdubs included maracas and extra drum fills at the end during the descending riff (on which Paul added a rhodes piano to double the grand piano).
All of this can be heard on the Phil Spector mix from the LP. Another significant difference is the fact that the end of the song is edited in order to add another pass at the final chorus just before the end riff. There is also a tape delay on the high-hats added during the second verse on the second version.
So there you have it: first version (Glyn Johns mix) with the tremolo guitar solo, shorter song, minimal backing vocals, no brass, no Linda) and second version (heavy guitar, additional chorus, backing vocals with Linda, brass, maracas, Rhodes piano at the end).