ferksake, what a pretentious thread title I came up with.
Anyway here's some mighty funky rhythm guitar from Marvin Sewell with Cassandra Wilson's group. How does he get that massive tremeloe - loosening the strings & hitting them so hard, loosening the neck bolts & flexing it, bending the fretted chords (def plenty of that) ? Some other method - Adam are you there ?
Very nice. A good compressor pedal will give you that boxed in sound. Whacking open light guage strings very hard will cause them to go sharp momentarily before settling on to the note you played. A trick famously used by John Lennon on The Beatles "Helter Skelter".
Don't mistake Tremolo for Vibrato - Tremolo is a change in loudness, Vibrato a change in pitch - which is what this is.
You can do it electronically. Some old amps (Ampegs and Magnatones) had it built in. A lot of modern amps have a built-in signal processor with a vibrato option. He's using what looks a pair of modern Fender Twins which so far as I remember don't have any effects built in. So if he isn't doing it with his hands (and he doesn't appear to be bending either neck or strings particularly fiercely) he's probably using an effect. At 1:53 you can see he's got three pedals in front of him. I'm not enough of a trainspotter to identify them I'm afraid.