Brendan Benson and Jack White of the Raconteurs ... more hooks than a fishing rod sandwich. Photograph: Graham Trott/Rex
Debate continues to rage as to whether the guitar solo is a vestigial organ waiting to be gently removed from pop's lexicon with a scalpel, but surely the riff is sacred? The best riffs, like the White Stripes' Seven Nation Army, can become the entire song and lay waste to our fussing over the finer points of structure.
A riff is usually defined as a short, repeated musical (melodic or rhythmic) idea, similar to the term ostinato in classical music. Although most often associated with jazz and rock, riffs inform different styles from Prince's Sign O' the Times (surely an inspiration for the sparse R&B of Missy Elliott and the Neptunes?) to the early synth-pop of Depeche Mode's Just Can't Get Enough. So, in such a wide field, what do great riffs have in common?
Silence
Don't be afraid to leave some space for the music to breathe. Black Sabbath's War Pigs leaves a huge gaping hole of two bars filled only with the hi-hat ticking away in the verses before Ozzy comes in. Then in the chorus this space is filled with pounding drum solos and the second half of the riff, which has remained absent until now. Back in Black's awe-inspiringly simple three-chord riff achieves similar crunching power through judicious use of silence. I'm not sure if this would be as effective however without the guitar licks at the end of each riff, which brings us to ...
Rhythm
There are at least two rhythmic factors that many genius riffs share:
1. Syncopation: Syncopation is when an accent is placed upon a weak beat or in-between the beats of the bar. In Van Halen's Jump, only three notes from the keyboard riff land on any beat of the bar. Beyond this, there are two specific ways in which syncopation can be used to boost a riff. Firstly, by pushing the first beat of each bar. Metallica's Enter Sandman, Michael Jackson's Beat It and Judas Priest's Electric Eye all place the first note of the riff in-between beats four and one, which has the effect of driving the music forward. Secondly, to begin the rhythm on the beat, but then shift it to the offbeat. This can enliven even the most stodgy meat-and-potato riffs (stand up Smoke on the Water), as well as providing with us some of history's most swinging motifs with the Stones' Brown Sugar, NERD's Lapdance and Judas Priest's Breaking the Law which all begin on the beat and then go off track.
2. Swing: The use of a dotted, swung or triplet rhythm to give the riff a bounce. Deep Purple's Black Night is an obviously swung rhythm in the guitar riff, but the swing can be as much to do with the drummer. Thrash metal isn't a genre one would normally associate with swing but Slayer's Dave Lombardo manages to add considerable groove to songs like Blood Red, as did Bill Ward in Black Sabbath.
Melody
The staple of the rock riff is the power chord. This is just the root note and fifth (with optional octave, played with distortion a la Back in Black). However, the more melodic riffs also have some common ground.
1. Blues scale (most commonly root, minor 3rd, perfect 4th, augmented 4th/diminished 5th, perfect 5th, minor 7th) If you want your riff to have a cock-rock swagger reminiscent of Led Zeppelin then base it on the blues scale. For further study, listen to the aforementioned Black Dog (blues scale in A) or Whitesnake's Still of the Night (in F#).
2. Getting more metal If you want your rock a little less cock and more shock, then you need to introduce some extra measures. For the classic twin-guitar metal sound you need to take your riff and shift it up or down to harmonise it in thirds. Iron Maiden perfected and pioneered this after nicking the idea from Judas Priest and Thin Lizzy. The perfect example is Iron Maiden's Iron Maiden. Bring in one guitar and then introduce the other a few bars later.
3. Serious evil Surely the success of Jaws introduced a generation of guitarists to the power of the semitone? Using the semitone from the tonic instead of the tone will introduce a sinister note, but if you want to get really nasty it is the tritone you'll need. Black Sabbath practically invented proper doomy, satanic metal on the eponymous Black Sabbath using a riff of three notes, employing only the octave and the tritone. The tritone is a augmented 4th/diminished 5th, which has no place in the natural harmonic series and has been associated with evil for hundreds of years, and was termed the Devil's Interval.
However, perhaps the most evil riff in history contains none of these elements. Its evil is manifested in a different way as a baby-sick green, anaemic aural assault. And the worst insult is that it's played by a great guitarist. Slash, what were you thinking when you played the riff to Michael Jackson's Black or White? Like Hanson trying to play Prince - no, no and no again.
In today's pop climate, the riff is out there and alive, being nurtured by everyone from Black Mountain to the Raconteurs. So let's hear what you think are the best and worst riffs of all time ...
