Dividing the parts to melody and accompaniment by: David from www.piano-play-it.com
Hey you :)
So in your picture I see quite an old instrument which immitates the look of the organs in churchs.
The idea behind this instrument is to use the upper keyboard for the melody and the lower one with the left hand for the accompaniment.
What's nice about this instrument is that you could set two different sounds for the melody and the accompaniment.
By the way, at your feet you will find pedals. These pedals can be used to play the bass with your feet so you're basically getting an all in one instrument.
Now, working with all the options in this instrument demands quite a training and some motorical abilities.
I'd focus first on playing the melody on the upper keyboard and accompaniment on the lower one.
Let me know if you succeeded. Post yourself playing something for us. I'd love to see it! :)
Hope I helped you... If you have further questiong on this topic or any other topic don't hesitate to ask me.