There are many important factors in music: harmony, melody, tone, concept, and so on. But if I had to pick just one, I'd have to choose rhythm. Harmonic and melodic concepts are truly important, but the rhythmic factor is crucial for delivering a coherent musical statement. So much so that rhythm is present in every musical expression (harmonic rhythm, melodic rhythm...), which makes it all the more significant.
Within each style, we can change the harmony and even the melody, but the rhythm has to be consistent with the style.
If we take all of the above and apply it to the guitar, we run into the classic division between rhythm guitar and lead guitar, a historical division I don't really agree with, since deep down, as far as rhythm is concerned, they're practically the same thing, even if one carries the harmonic line and the other the melodic one. Delving into rhythm guitar, we need to highlight a few concepts, such as voicing, that is, the arrangement of the notes in a chord, rhythm itself, tempo, and tone, so as to blend in with the rest of the band. Let's go through each point one by one.
RHYTHM/TEMPO
As we said in the introduction, rhythm is the most important factor when it comes to playing any instrument. So let's give it the priority it deserves. If we understand rhythm as the arrangement of notes in time, we're talking about something mathematical; analyzed coldly, it consists of dividing time with marks or guides and placing notes in line with those marks. So it gives the impression of being relatively controllable. However, it's a much more complicated concept than it seems, because it's not just about intellectualizing but also about internalizing a feel when playing, and that isn't easy. This is where our own talent, or the natural ease we have (or don't have) when facing a rhythm part, comes into play. But since talent isn't enough to solve every possible rhythmic problem, we should try to gather as many tools as possible to handle any rhythmic situation that comes up.
On the other hand, we need to clarify the concept of tempo, which we can define as the marks that guide us in placing our notes. If we play with a metronome or a sequence with perfect time, those guides are evenly spaced, but since we're human and make mistakes, we'll never have perfect time. However, even though we can't play exactly "on tempo," around each metronome click there's an interval or window within which the ear perceives that we're playing "in time." More specifically, there are three positions we can place ourselves in: Rushing, Laid Back and On Tempo. Taking a single metronome click as our starting point, we can choose to play slightly ahead of that click (Rushing), slightly behind it (Laid Back), or right on time, as close to perfection as possible (On Tempo). In many cases, it's preferable to play behind (Laid Back) or right on time, as close as possible to playing on the beat. Only rarely do we aim to play ahead (Rushing), since it conveys a sense of nervousness. But it has to be said that in certain circles playing behind the beat is overrated (personally, I think playing right on time, and therefore as close to the metronome as possible, is a solution that works in almost every case). In any case, these three concepts will help us control many situations that can make something that seems really simple become complicated.
The conclusion is that, if our role at a given moment is that of rhythm guitarist, we need to focus on whoever leads rhythmically in the band, in most cases the drummer. This means we have to lock in tightly with the bass player and the drummer and try to sit in the same position on the beat, so that we sound very cohesive. Once again, playing with something that has perfect time, that is, a metronome or a drummer playing to a click, helps keep us from speeding up or slowing down and gives us better internal time.
HARMONY
Having explained the concept of rhythm, we now have to talk about the harmonic side. As rhythm players, we need to know the chords that make up the song, as well as their order, and figure out what the bass is doing, so we can find a way to fit in between it and the lead guitar, keyboard or singer. In other words, we have to work out which position and which register to play in to find our spot without getting in our bandmates' way. To do this, it's highly advisable to study all the inversions and melodic triads of the chords, and on top of that the intervals, that is, thirds, sixths, fifths, etc., all over the neck, since we don't know what we're going to need or which register we'll be asked to play in.
All of this also varies depending on our situation, which will largely determine our approach; in other words, depending on the style we're playing and the band's lineup, we'll approach rhythm guitar one way or another. If we're accompanying a singer, we might have a bass and percussion and even another guitar. If we don't have many instruments, we should consider increasing the number of notes per chord, since we need to cover most of the spectrum. As the number of instruments increases, we should think about using as few notes as possible, but with the maximum amount of information. On the other hand, we need to pay attention to the style of music we're playing, since it will shape our voicings. For example, if we're playing a jazzier/fusion repertoire, stacked fifths shouldn't be our priority, but if we're playing a rock repertoire, that same interval is more than advisable. So we should bear in mind that, just as there's a lead guitar vocabulary that we have to match to the style we're playing, exactly the same thing happens in the field of rhythm guitar.
TONE
The last notion to keep in mind is timbre itself, which we use to finish shaping the previous concepts and which, once again, depends on the style of music we're playing. For pop/rock, guitars like Telecasters or Gibson SGs work very well for rhythm. If things get even more over the top and we want a really hard-hitting sound, we should think about Gibson Explorers. Of course, these are just examples that generally work well, which doesn't mean each of us can't have other equally suitable formulas.
In terms of amplification, rhythm guitar is much more flexible than lead and lets us relax about which pedal to use or not. It's a kind of guitar that doesn't usually change its sound much over the course of a set.
RHYTHM GUITARISTS
In this last section we'll look at a few guitarists known, among many other things, for doing great rhythm work:
• MALCOLM YOUNG:
The eldest of the Young brothers, a founding member of AC/DC, is one of the great rhythm guitarists in rock history. His concept of playing with a lot of weight and a crunchy but powerful sound has made him the heart of the band. His guitar is a Gretsch Jet Firebird that he has kept for years.
• JAMES HETFIELD
The singer and rhythm guitarist of Metallica is known for his frontman skills, but his great rhythm work sometimes goes largely unnoticed. He spent much of the '80s and '90s equipped with his Explorer and Mesa Boogie. His right hand can play riffs with downstrokes only, faster and more precisely than what we can manage using alternate picking.
• SCOTT IAN
When it comes to heavier sounds, let's think of a band like ANTHRAX, which has Scott Ian in its ranks, with a great sound and, above all, great time and rhythmic ideas.
• IZZY STRADLIN
He was the rhythm guitarist of Guns N' Roses, the band with which he wrote quite a few hits. He was usually seen with a Gretsch or a Telecaster. His great crunch sound and his low profile made him a cornerstone of one of the best-known bands in the world.
• STONE GOSSARD
The quintessential rhythm guitarist of the grunge movement. Stone Gossard plays in Pearl Jam, and much of the band's songwriting falls to him. This musician can get away with anything, although he's often seen with Les Pauls, Strats or Telecasters.
• DAVE GROHL
Nirvana's former drummer went on to lead a band in which he played guitar and sang. His great time stands out, possibly thanks to his background as a drummer. His main guitar is the Gibson Firebird.
We could make this list go on forever, but I think that, within rock/pop, these are fairly popular examples and perhaps, the next time we listen to them, we'll do so with different ears.
CONCLUSION
Throughout this article, we've tried to show the importance of rhythm guitar. We should think of it as just as important as lead, or even more so, since it's what makes the songs work and, above all, it's responsible for making life easier for the singer or soloist.