Yamaha has had dynamic accompaniment starting with the PSR-2000...it's on the Tyros1/2/3 and the later mid line PSR as well.

It is called "Style Touch"

The PSR-6700 also had it in a slightly different form, although it did basically the same thing...that was around 1990...it was called "Interactive Accompaniment".

I also encountered this type of feature on the Roland E-70,back when I did demos for them (around 1990 or earlier)...they called it "Arranger Velocity Level".

So it's been around for some time, although I don't tend to use it a great deal.

It must be on the E-60?

Ian