At least, Metallica’s version uses a flatted fifth.
In Renaissance music, composers wouldn’t use a tritone. In performing polyphonic music, when two lines would be making a tritone against each other, you alter one of the pitches a half tone to avoid it. These days the editor marks an accidental in the music, but supposedly Renaissance singers knew their theory well enough that they would just know to make the change even though it wasn’t written in. The changes are called musica ficta. Since we don’t know exactly what the rules were, there are a lot of competing theories about exactly when and how accidentals should be added. (This is just what I’ve picked up in choruses, so it may be a bit simplified.)
Wait, that’s right. And a flatted fifth is a tritone. I believe you’ve vindicated me, Diogenes. 
Glad to do it, pravnik. It’s all in the name of fighting ignorance. 
Sez Yoo.
My high school choir sung that sort of stuff all the time. Choral jazz is great.
i’m the only one who thought of the opening lines of Leonard Cohen’s “Hallelujah” ?
not the devil’s chord, admittedly, but apparently g-d likes
“the fourth, the fifth, the minor fall, and the major lift”
sorry, please carry on.
So I should stop using that bit of song to tune timpani?
no… the Wicked Witch of the West’s guards chanted a perfect fifth-- NOT a diminished fifth (tritone).
you are NOT vindicated.
Biffy the Elephant Shrew wrote
Of course. Thanks.
One place you’ll hear the tritone fairly often and not find it awkward or painful is when it resolves to the major chord rooted in the tone that would be the fifth to the tritone (i.e., one-half step above the upper tone of the tritone).
Example: play the C and F# combination mentioned by Billy the Elephant Shrew. Then resolve to a G major chord with the G just above the F# crowning the chord.
What you’ve done is utilize the tritone combination as elements of a D7 chord. If you wish, throw in an A below the C, and ground the chord with a low D and then resolve it to the G chord, and it sounds even better.
I don’t know about the real version but I promise you that Metallica uses a flatted fifth in their version. They play it as an intro to their song “Frayed Ends of Sanity” and they play the two chords as E and B-flat. Maybe they’re doing it wrong but I guarantee that’s what they’re doing.
DtC–
I do not know the Metallica song-- I was referring to the chant of the witch’s guard in “The Wizard of Oz” with Judy Garland.
Not sure which is the seminal version, but I could guess.
So now I wonder what happens when you watch The Wizard of Oz with Metallica on instead of Dark Side of the Moon.
Thanks to all those who gave examples like the Simpsons and Purple Haze, so we non-music majors could get a handle on this topic.
It sounds to me like there are a group of tritones in the guitar solo in “Dirty Laundry” by Don Henley/Eagles. Is this correct? It sounds so incredibly cool.