It’s weird to hear any song from Side Two of Abbey Road on its own (with the exception of ‘Here Comes the Sun’). ‘Because’ isn’t an official segment of the 16-minute medley that makes up most of Side Two, but it may as well be.
John Lennon said that the inspiration for this track came to him when he heard Yoko playing Beethoven’s ‘Moonlight Sonata’ on the piano. He ask her to play the chords backward and built the song around that progression.
‘Because’ features John, Paul and George harmonizing throughout, and is supposedly the only Beatles song performed start to finish by all three of them. George Martin triple the vocal track so it sounds like nine Beatles harmonizing.
Because the world is round…aaaaaahhhhhh
Because the wind is high it blows my mind
Because the wind is high…aaaaaaaahhhh
Love is old, love is new
Love is all, love is you
Because the sky is blue, it makes me cry
Because the sky is blue…aaaaaaahhhh
Aaaaahhhhhhhhhh…
Meet Me In Montauk 
I always considered this part of the b side medley as well. The last chord leads so nicely into the next track.
I had never heard about the “Moonlight Sonata” inspiration or the fact of all three singing start to finish. Good stuff.
This always strikes me as a particularly trippy Beatles’ song, and your description of how it was made certainly explains why that might be. It’s an odd one to hear as a stand alone song, but that’s what random weekends are for… this does feel random 😉
Neat story about the “Moonlight Sonata”