Hi Nobby...

there is some more about aftertouch...

we decide channel aftertouch, which means you have only one aftertouch switch for the whole keyboard. For this, below all the keys there is one long resistor ribbon. If you press one key harder, the resistor is lowered and the aftertouch is switch on, controlling e.g. the pitch of a blues harp sound. But you are not able to control each note you're playing individually, if one key is pressed harder, the whole chord is changing (eg. volume, pitch bend, modulation, brightness and so on, depends on the midi controller you've assigend to the aftertouch function).

If you have a polyphon aftertouch (much higher in price) you can control each key individually. And this is much more complex to play...
are you able to play a five finger chord, where you press the thumb and the middle finger harder?

Greetings

Datablues