The groove is like a membrane containing a living breathing organism that travels in the realm between the beats. To realize the groove is a task in itself. A groove is not just a beat. It is a combination of a beat and the varying dynamics from the different musical lines that run counterpoint to each other. The dynamic swells create a beat within a beat, and together they form a living breathing groove – the heart and soul of the song. A groove can be created with a single instrument such as an acoustic guitar. The simultaneous musical lines of bass, rhythm, and hook or lead line running in a well-constructed rhythm guitar accompaniment, for example, can fill every need of the song and provide the listener with an extremely dynamic experience.
This approach can also clearly map out the other accompanying musicians’ parts all contained within a single guitar/piano part. If the rhythm section is dynamic, the singer or soloist’s performance can be more inspired. A single work, phrase or thought can be reinforced with a dynamic swell, thereby enhancing the lyric and, ultimately, the song. The fact that the dynamic swell recurs throughout the song allows the groove to be reinforced.
If these elements of dynamic interchange are cautiously and sparingly introduced to the arrangement of the song, the results can be startling. For example, when I have completed the melodic and dynamic arrangement on acoustic guitar for one of my songs, I check its dynamic integrity, groove, bass, lead (or hook), and rhythm lines by muting my strings with my chording hand and picking and strumming on the muted, note-less strings. Then I try the vocal or instrumental melody along with it. The song should still hold together beautifully. Believe it or not, actual notes are not necessary to hold a song together. They simply become a functioning percussion part that one can sing or play melody to. Basically, this also provides a clear map as to time feel and dynamics for the drummer. If no groove is present, the part becomes metronomic and devoid of life.
This can also free up my creative process during composition by allowing me to become a bit more abstract in choosing chords and melodies for the rhythm guitar accompaniment. Some of that weird angular stuff we hear in our mind’s ear is pretty cool. All we have to do is extract it.
If the artist has the rhythm and groove mapped out inside their own accompanying instrument, a rhythm section can easily extrapolate a useful accompanying part from it. For example, the brush of the pick fanning the strings on an acoustic guitar can indicate, or perhaps allude to, a hi-hat rhythm. The bass line played within the acoustic guitar part can provide the foundation for the electric bass and kick drum, and also the hook line for the lead guitarist, and so on.
Inside this extrapolation process, remember less is more. When in doubt, leave it out. For example, maybe the bass line can be reduced to emphasize only specific points of the groove. If you play two or more bass notes really close together, they can’t open up and reveal deep, low frequencies; these are choked out. The same thing with the kick drum; it can’t go boom! If you only give it space for buh. If a hook is not present, then you may have to hunt one down. Where? In the melody, I suggest. It’s loaded with useful notes.
Sometimes the musicians have only been given a rough outline of the song before arriving at the session. Let’s assume the artist has provided them with only a vocal and accompanying acoustic guitar rhythm. How can they be expected to know that the producer or artist wants them to wax melodic on a sax solo or swing the beat on the hi-hat? Somebody has to have thought these things through and must communicate them to the supporting musicians. Otherwise, the lead guitar part, for example, may be colliding with, or drowning out, the vocal line. The kick drum and bass line may not be lining up or making sense together. Or perhaps something in the strumming of the acoustic guitar is washing out the hi-hat.
Somebody has to be vigilant during this [process or, in a “wave cancellation” kind of way, one part will wash out another. To illustrate this, have three acoustic guitar players – adding one guitar at a time – strum the same chord in the same position with the same rhythm. A thin sound will be come thinner and more vague. Now have each guitarist play a part in a different octave or position, counterpoint to each other, keeping the parts sparse. Now hear the sound grow! Finally, have each guitar part take on a different dynamic pattern, again counterpoint to each other just like a percussion section would, and enjoy a living breathing groove.
Good luck and above all, have fun.