A very powerful yet simple element to use when playing rock piano is slash chords. This means that you play a chord over a different bass note than its root. So while you would normally play a C chord over its root C in the bass, you can also play the same chord over different notes, such as D, E or F.
This way you will get a different sound for each of the resulting slash chords, which then are written as C/D, C/E or C/F (you read it as C over D, and so on). While technically rather easy to play – you just move around the bass note on the keyboard, while the right hand chord stays in place – the resulting sounds are often interesting or even impressive.
Here is an example of a chord progression with slash chords. The right hand A minor chord stays in place, while the left hand plays the different bass notes A, G, F and E. When it comes to D, the right hand chord changes to D minor 7 and the last chord in the sequence is G major.
D minor 7 – 2nd inversion
G major – 1st inversion
It also sounds well if you play all chords up one octave in the right hand.