If you want to become a good pianist or great keyboardist, no matter what you do, you will have to learn the concept of musical rhythm. So here’s a quick introduction.
Rhythm is the placement of sound within a time reference. If anything, it is what differentiates a classical piece to an electronic dance music song. It can be very different from pieces to pieces. So you better know how to read it and reproduce it when playing a score.
There are basically two main elements to remember when learning rhythmic expressions: note duration and musical beat.
On Dodeka sheet music (and more generally in the Dodeka music notation) note duration is described in visual and graphical terms. As notes are represented through rectangular shapes, their duration is conveyed through their length. The longer a note is, the longer it should last. (It’s similar to what you can find on sequencer software). Following this principle, quarter notes being the reference, half notes are twice longer, whole notes four times bigger, eighth notes half the size and so on.