Time as written in music notation is divided like you divide up a pie, in half notes and whole notes and quarters and eighths and sixteenths. (actually, we never divide pies into 16, that would be cruel.) For each note division there are also divisions of rests as well, or divisions of silence. This is a start for the idea of time and rhythmic division and we will continue on this topic as we move forward.
For now think of your foot establishing beat or pulse and your right hand defining and dividing the pulse into rhythm.
These are core essentials for the beginning guitarist that will effect everything you do moving forward, the conceptual understanding of time and beat and rhythm as they apply to the guitar are fundamental to building a strong technique and musical understanding.
Think of the down beat being quarters and when you strike the upbeats think of these as the eighths. Solid down and up should be counted:
1 and 2 and 3 and 4 and
This would be solid eighth notes, the downstroke on the quarters or numbers or downbeats and the upstroke on the and or upbeats. That is a great place to start.
Don’t break the down and up of the right hand and always make sure to keep the downbeats in the right places or you run the risk of turning the beat around or upside down.
Try synchronizing your foot with your hand, foot goes down, right hand goes down, foot goes up and right hand goes up. With guitar rhythm playing the right hand literally follows the down beat and the upbeat. The more upbeats and the fewer downbeats the more the rhythm is syncopated.
A very unsyncopated rhythm is a march, strongly syncopated rhythms are often found in Latin and African and Jazz music. Guitar players are most often required to play a rhythm and accompaniment role so getting a solid rhythm playing style and concept will be important.