I want to know the origin of I → I7 → IV → iv. I have a vague sense that a lot of songs do it, but I can’t come up with any besides “Desperado”.

“Dear Prudence” is sorta close, as is the end of the chorus in “I Saw Her Standing There”.

     [G]   [G9]               [C]          [Cm7]
Desperado,      why don't you come to your senses

(For this thread, let’s just say “G9” is in the class “G7”.)

A couple weeks ago, we had a thread about "Build Me Up Buttercup", which has a nice I → I7 → IV → iv at the end of the chorus:

       [C]            [C7/Bb]             
I need you, more than anyone darling, 
    [F]                       [Fm/Ab]
You know that I have from the start

Also a couple weeks ago, Merrie and I let Avery and Kelsey watch "The Little Mermaid", and while Merrie explained the plot to them, all I could think about was how in "Part of Your World", there's an awesome I → I7 → IV → iv:

              [F]                 [F7/Eb]
Up where they walk, up where they run,
              [Bb/D]              [Bbm/Db]
Up where they stay all day in the sun

Or, if you prefer a version that doesn't make any sense because she's not a mermaid:

Carly Rae Jespen - Part of Your World

Another example:

Frankie Valli – Can't Take My Eyes Off You

                [E]
You're just too good to be true
              [Emaj7]
Can't take my eyes off you
              [E7]
You'd be like heaven to touch
        [A]
I wanna hold you so much
             [Am]
At long last love has arrived
            [E]
And I thank God I'm alive

Good call, there are a huge number of awesome things about “Can't Take My Eyes Off You”. Amazingly, even this awesome song couldn't survive the all-distorted-driving-8th-notes-all-the-time attack of modern angst-rock:

Muse – Can't Take My Eyes Off You

On second thought, I'm going to elaborate on said number of awesome things to love about "Can't Take My Eyes Off You", and the IV → iv is barely even going to appear on the list. Holy crap I'm glad this song came up.

YouTube: Frankie Valli – Can't Take My Eyes Off You

Spotify: Frankie Valli – Can't Take My Eyes Off You

Oddly, this song is in E on Spotify, but in F on every recording on YouTube. This happened a lot with songs that were remastered at various times, stretched on tape, not exactly in standard tuning to start with, etc. I'm going to talk about it in E (but link to YouTube for time-specific links).

First, the intro chords are awesome. I'd call it "F#/E, F#m/E, E", so a II → IIm, but neither as odd as a II nor as boring as a IIm because it's all still over an E (I). Another way of looking at this is that the bass, which actually made a difference in 60's recordings because you could hear things in the mix, made a clever decision to just play the I. These chords also repeat at the end of each verse.

Frankie Valli – Can't Take My Eyes Off You (end of verse)

You're just too [F#/E]good to be true[F#m/E]
Can't take my [E]eyes off you

This is is the first thing I'm going to choose to dislike about the recently-popularized arrangement (Lauryn Hill and every YouTube cover)... they give this progression a sort of nod in the intro, but in the verse, they just play F#m.

Lauryn Hill – Can't Take My Eyes Off You (end of verse)

You're just too [F#m]good to be true
Can't take my [E]eyes off you

But back to awesome things about the original. We still have our IV → iv in the verse (where this thread started). Then we have this awesome horn part, maybe the hook of the song, that I don't totally know how to describe (also left out of the Lauryn Hill version):

Frankie Valli – Can't Take My Eyes Off You: Pre-chorus horntasticness

Chords are simple: F#m B E. But that horn riff is mostly playing this cool "C → C#" slide. The horn is playing C! Over F#m, B, and E! C! C! C! Craaazy!

Am I done? Fuck no! There's still an awesome key change coming!

The chorus is pretty squarely still in E (F#m A G#m7 C#m7):

Frankie Valli – Can't Take My Eyes Off You: Chorus

Also that bass is just super-classic, super-clear '60s bass. Mmmmmm!

...but the chorus ends an a super-cool (though not astonishing) D7 (VII):

Frankie Valli – Can't Take My Eyes Off You: Chorus ends on a D7

Then back to the verse. In E again, right? No! In G! Super-not-jazz-sounding-1.5-step-key-change-alert!

Frankie Valli – Can't Take My Eyes Off You: Second verse, now in G

But *surely* when they go back to the bridge again, it would sound weird to go back to E, right? Right? Hell no, back to the original key, and it doesn't even sound weird!

Frankie Valli – Can't Take My Eyes Off You: Second bridge (back in E)

Last thoughts here on the Lauryn Hill version... I basically disagree with every decision:

1. Taking out the cool II/I → IIm/I
2. Taking out the cool bridge
3. Taking out the key change
4. Doubling the pacing of the lyrics in the verse (i.e., changing chords twice as often without changing time)

BUT... I do like covers that change stuff, so I like the concept. (4) (i.e., doubling the pacing of the lyrics) is particularly interesting; I'm 53% against this change, but I can't think of other covers that do this.

In summary, I can't take my eyes of off the chords to Can't Take My Eyes Off You. My full transcription here.

I agree, this song is totally awesome. And there's even another awesome thing about it that you didn't mention, the 7#9 chord right before the chorus! I think you have it down as a C#7 chord, but it's really a C#7#9 and it's perfect.

In fact that whole prechorus may be the best prechorus ever, and I sure do love me some prechoruses.

The I → I7 → IV → iv part of this thread reminded me of "It's My Party" by Lesley Gore, though the internet disagrees on whether the second chord is A7 or A+.

Lesley Gore – It's My Party

[A]It's my party and I'll [A+]cry if I want to
[D]Cry if I want to, [Dm]cry if I want to

It seems pretty clearly to be A+ to me, at least going by the backup singers and (I think) the bass. Though if it were A7 it would have a nice descending quality to it (A G F# F).

Raja, good call on "It's My Party", and way to reach into the archives. The iv is actually pretty subtle... the guitar is just tiny staccato hits that are almost inaudible, and the vocals are just singing A over all four of those chords (A A+ D Dm), so the chord movement is almost entirely defined by the also-pretty-quiet backing vocals, which are doing E F F# F, where that "E" is the first-string-twelfth-fret E that guys can't sing, so it's all off in the ethereal head-voice. So, bottom line, good catch on that iv.

Then on top of that, if you had stopped me on the street and asked me to classify this song as "lots of interesting chords" or "another standard '60s I vi IV V song", I would have guessed the latter. But in fact the verse has more non-diatonic chords than diatonic chords! II, bIII, and bVI!

[A]Nobody knows where my [C]Johnny has gone
But [A]Judy left the same [D]time
[F]Why was he [A]holding her hand
When [B7]he's supposed to be [E]mine

And while we're on the topic of Lesley Gore, *two* very cool and very different key changes happen in "You Don't Own Me", first when the verse (in Gm) rolls into the chorus (in G):

Lesley Gore – You Don't Own Me

[Gm]You don't [Cm]own me [D7] don't say I 
[Cm] can't go [D7]with other [G]boys 
And [G] don't tell me what to do 
And [Em] don't tell me what to say

Then later that chorus in G moves in a non-gratuitous way to Ab:

Lesley Gore – You Don't Own Me (key change)

Oh, I [G] don't tell you what to say
I [Em] don't tell you what to do
So [C] just let me be myself
[D] That's all I ask of you

I'm [Ab] young and I love to be young
I'm [Fm] free and I love to be free
To [Db] live my life the way I want
To [Eb7] say and do whatever I please

...then later to A, and then Bb, but I'm not really giving bonus credit since those are re-appearances of the same key change. Let's call it 2.5 total unique key changes.

Man, it's too bad we never got to see these classic songs cast as over-the-top '80s videos like the ones that have come up on so many other threads. But wait!

Lesley Gore – You Don't Own Me ('80s edition)

Goodness, I'm totally obsessed with I → I7 → IV → iv now.

Ian mentioned “I Saw Her Standing There”, which has a I → I7 → IV → bVI :

So [E]how could I [E7]dance with an[A7]other [C]oh

As Ian implied, if you squint, this is the same as I → I7 → IV → iv (E E7 A7 Am). Now that Ian made this connection, I'm starting to see these crop up all over too, and I have a new favorite in this category:

The Brady Bunch – Keep on Movin'

The [D]wheels are humming and the guitar's strumming
and the [G]radio is blasting and [Bb]good sounds are coming
as we're [D]flying down the highway in a [A]makeshift Model T.[D]A.

Holy shit was TV bad when there were only three channels, but you can't say this song isn't catchy.

And another! They're everywhere I look! This time we've made it full circle; this thread was originally called "Eagles chords", and it's once again about Eagles chords. Previously this song came up on another thread, about how he sings a Bb over this whole phrase in G (which is awesome).

The Eagles – Heartache Tonight'

There's gonna be a [G]heartache tonight, 
The [G7]moon's shining bright
So [C7]turn out the lights, and 
[Eb something]we'll get it right

This post was called "on the origins of I → I7 → IV → iv, but I don't think we ever got to the actual origins. Straw man (or straw woman) candidate: can anyone come up with an example from before 1902?

Scott Joplin – The Entertainer

Da da da [C]da da da [C7]da, da da da 
[F]da da da [Fm]da da da da da
[C]da da da [G]da da da [C]da