i'm not buying your latest hoo doo, uwe. imo the SONG is what matters first, it always matters first. riffs, chords or sitars need not apply. the music will attract the audience that likes it no matter who or what they are. i know being german everything has to examined, categorized and stored in a dust free environment. i think you hold up well under this obligation to your country. you should listen to more jazz. 
Of course a song is a song. But you can ice a good riff with harmonies and vice versa. I'm not sure Jumping Jack Flash would be the same if they had just chugged a B major throughout, but of course you can play it that way. You can also play Black Dog without the opening riff and Detroit Rock City strummed along to a C minor would have stormed the charts just the same. Likewise, Superstition didn't meed that riff, hitting the empty E would have done it too. Beethoven's 5th, no one would miss the intro, just like Brubeck's Take Five didn't need that 5/4 bass run. Alice Cooper's School's Out didn't need a riff etc ... Smoke on the Water is fine with that elaborate G/F harmony (also put to good use in My Woman from Tokyo), the riff had nothing to do with it conquering the airwaves, hey, and Highway to Hell sounds great just with an open A ...
Frankly, you have to be deaf not to notice that today's top twenty music offers a lot less riff oriented songs than the charts in, say, 1973. And the art of a lead vocalist singing a largely unrelated vocal melody over a dominant riff - a characteristic that defines most hard rock - seems to be a dying art. It's what I dislike about punk, it washed away riffs and made the bar chord the dominating musical theme. Try as I might, I hear more differences between the riffs of Kashmir, Smoke on the Water and Sabbath Bloody Sabbath than I hear in the umpteenth drone of D, A, B and G, which Olivia Newton John, Aha, Journey, U2 and dozens of others (I take exception as regards Maxine Nightingale's Right back where we started from, it used the same harmonies, but I like it, it also had an intro riff!) have turned into hits. It's a lot more difficult to swipe the Smoke on the Water or Enter Sandman riff and not get caught.
Does regretting the lack of a idiosyncratic instrumental musical theme in many of today's songwriting make me a dinosaur or a teutonic overanalyst or both? And while we're at it name me 10 trademark riffs of chart songs in the last, say, three years. I believe singers, producers and the music listening public have all adopted a certain arrangement laziness. If a melody is good today, you give it a simplistic backing and don't "clutter it up". However, some of the greatest rock classics are cluttered in arrangement by today's minimalist standards. What happens in DP's Burn alone (huge riff, wild drum rolls throughout the verses, neo-classical guitar and organ solos, a majestic chorus carried by two lead singers) would today never see the light of day but be dissected into three or four songs.
Where is my Blood, Sweat & Tears collection? ; - )
