What's The Frequency, Kenneth?

This parody (written by Greg Crowther) is sung to the tune of "What's The Frequency, Kenneth?" (written and performed by R.E.M.).

This song, which I dedicate to NMR guru Kenneth Marro, is an attempt to describe the basics of magnetic resonance, a popular clinical research tool. The basic idea is as follows: the patient is placed in the bore of a giant magnet. In this environment, the nuclei of the atoms in the patient's body align themselves with the magnetic field and spin around (or "resonate") at frequencies of billions of rotations per minute. (The exact frequency depends upon the type of nucleus under consideration and the strength of the magnetic field.) The relative amounts of the different types of nuclei can then be measured by exciting them with radiofrequency radiation and then measuring their spins as they relax back toward their initial state. This procedure is completely painless and is not known to cause any short- or long-term harm to the patient.

Jargon advisory: datum is the singular form of the word "data."

What's the frequency, Kenneth, at which these nuclei spin?
It depends on the strength of the field that they're in.
But each type rotates at a rate of its own,
So we can target some and leave the others alone....
Into the magnet the patient will slide, uh-huh.
We'll learn the secrets his atoms confide, uh-huh.

Magnetic fields will force these nuclei to behave
'Til we excite them with radiofrequency waves.
Then we'll detect their spins as they start to relax --
It may sound strange, but these are the facts....
Into the magnet the patient will slide, uh-huh.
We'll learn the secrets his atoms confide, uh-huh.

What's the frequency, Kenneth, at which these nuclei spin?
It's on the order of several billion cycles per min,
But the exact rate is different for each type of atom,
So you can ID an atom with this datum....
Into the magnet the patient will slide, uh-huh.
We'll learn the secrets his atoms confide, uh-huh.
Inside the magnet the nuclei dance, uh-huh.
Do you understand?
This ain't no x-ray; it's much more advanced, uh-huh.
Do you understand?
Into the magnet the patient will slide, uh-huh.
Do you understand?
We'll learn the secrets his atoms confide, uh-huh.
Do you understand?