The Major Chords I-IV-I-V-I
We saw in the I-V-I progressions how the V chord exerts a strong pull to return to the I chord. The IV chord, on the other hand, PROPELS the music forward, but there is not necessarily a pull to return to the I chord. In fact, the IV chord could just as easily go to some other chord. The IV chord makes the music more exciting to my ear. Here is a sample of a I-IV-I progression that then goes into a V-I to form a I-IV-I-V-I (if I didn't say it before, pronounce all those Roman Numeral numbers as, "one, two, three, etc.") progression overall. I have to say that songs are made up of small chunks of chord changes that are added together to form a tune. So, try to familiarize yourself with the distinct sounds of the different chords changing. We heard how I and V sound when changing. Now let’s introduce a IV chord into the mix. Try to pick up when the music goes to the IV chord, and how it drives the tune forward. Here’s an MP3 excerpt from “Corinna, Corinna” to illustrate the I-IV-I-V-I changes. The excerpt of the tune is 372KB.

I have also created a Flash 6 file for "Corinna, Corinna" that plays the song and graphically shows the changes as they happen. To view this file, you will need to get the latest Flash reader software. Right-Click (PC) or Control Click (Mac) on the image when it comes up, and select "play" to start the sound. Select "Rewind" then "Play" to hear the song again. Select "Loop" to play the song repeatedly.

The bass is a hard, thumping, walking bass line that should make the changes obvious by ear:
The changes go:
I I I I
IV IV I I
V V I I