What he's really talking about is chord progression (while he doesn't really say that, it's essentially the description of his first few paragraphs). Most university-level music classes discuss common chord progressions. As he notes, the I, IV and V chords are the most common to appear in a song.
It's a great article, but I think he may have done a lot of work to find out something that is fairly common knowledge lol. Still cool though to have the supporting data. (edit: it would be cool to make this an interactive piece of data presentation to help you write songs. Also, the I, IV and V chords are so popular because they naturally make people feel good. It's why they show up so often in 'pop' music. minor chords have a more depressive quality to them)
Also, if you need proof that certain chords show up often in music, just listen to some Nickelback. Here is a fun link (that I THINK works. my speaker only works in the left side ;) )
http://dagobah.net/flash/nickelback.swf
Hi horsehead, I don't know if you made it to the Music Editor part of the site http://www.hooktheory.com/editor but you can use the Music Editor to write songs using I V IV (type 1,5,4 on your keyboard) and such. One of the main goals of Hooktheory is to make more people aware of these basic elements of music theory and help people incorporate it into their musical endeavors.
It's a great article, but I think he may have done a lot of work to find out something that is fairly common knowledge lol. Still cool though to have the supporting data. (edit: it would be cool to make this an interactive piece of data presentation to help you write songs. Also, the I, IV and V chords are so popular because they naturally make people feel good. It's why they show up so often in 'pop' music. minor chords have a more depressive quality to them)
Also, if you need proof that certain chords show up often in music, just listen to some Nickelback. Here is a fun link (that I THINK works. my speaker only works in the left side ;) ) http://dagobah.net/flash/nickelback.swf