Not so deep as Lady Madonna, but he still has a great, unique vocal style on Nineteen Hundred and Eighty Five. Even in live in 2010:
“Jet” is in the key of A, like Lady Madonna. The verses are sung in the same range, but with less affectation. I remember hearing the first time thinking, hey, it’s the Lady Madonna voice. The voice used on LM on Wings Over America is a bit forced I always thought.
I love the song, but I really hate his fake voice on the recording. Glad he didn't use it more often than he did. Probably just a thing he thought was amusing for a year or two.
I also have thought that Paul’s “Fats” voice sounded more like Elvis. This would have been such a natural cover ... maybe the lyrics were too weird. Right before this fades you hear him ask “are you guys hungry?” and I guess that was that for Elvis’s version of LM.
I remember a contemporary review (Time Magazine?) where it was described as singing in an Elvis voice, so you have company.
To my ears, Paul's Elvis voice is best heard on That Would be Something...I would've loved to hear Elvis record it although he probably wouldn't have been too "keen" on it, lyrically.
The Lady Madonna style is one of my least favourite McCartney styles of singing. It sounds fine where it is but I wouldn't want much more of it. It's always been my least favourite Beatles single. That doesn't make it bad!
It's a little sarcastic, brassy, and world weary in tone. I think it came in first with Paperback Writer. I think it was his trying to emulate Johns style more.
..my least favorite single as well along with From Me To You. Best that I can think of at the moment, the closest Paul came to using that voice again was during the second section of You Never Give Me Your Money.
I hear a different tone entirely throughout those sessions in January of '69. It's an interesting high pitched texture he used on Get Back, TLAWR and very evident on the harmony vocals of 909, Dig a Pony and also on Ballad of John and Yoko. I hear this tone, also, on Ive Got A Feeling. He also used it on Oo You.