A good friend of mine was watching the movie American Graffiti again (probably for the 500th time) and pointed out to me the similarities between the logo used for the movie and the American Idol logo.
Released in 1973, it was written by George Lucas and has been deemed an American classic. I'm not going to go through the whole plot (that's a chore for Wikipedia) but it will simply suffice to say that it's a coming-of-age story that is set around the music of the early '60's. What's key to keep in mind is the whole movie's emphasis on its soundtrack, with many of the songs essential to the flavor of the movie. These songs were just starting to become entangled in the fabric of "Americana," and they certainly are that way today.
Consider the American Graffiti as it is presented below. This version was depicted on the advertising posters and later DVD covers.
Now take a look at the American Idol logo below, which has been used not only for the broadcast but (interestingly enough) on products related to the show which sometimes included special edition perfumes.
I view it as no coincidence that the ever so popular American Idol should use a logo that is very similar to one which has come to represent a cultural icon. I see this as the continuing of a tradition: that of the impact music has to America's youth, and has had since the '50's and '60's. It is a tradition that we can't shake and is proven by the huge numbers of viewers who watch American Idol every week and root for thier favorite singer, going all the way back to American Bandstand.
Lastly, look at the "photoshopped" composition below: it combines the two above mentioned logos to show just how strong the similarities are. They are basically idenitical (except for a more exagerated slash on the A).