cool,i wanted to do some circuit bending myself

This is interesting because at the end of the ride is still a large deviation. I am thinking of dj equipment potentiometer.
But thank you for your help. I'll get back even if you managed to fix it.

the leftmost wire looks like its going to a ground, should be fine.  worth checking though

try lowering the resistance of the pot.  it sounds like a log pot whose resistance is too high.  since there is a noticeably steeper rise in it.

if you have a way to measure what the nominal maximum value of your pot's resistance is (if you have a multimeter, that is), check it's value and then use whatever type of pot you want with that resistance value.  your bend (taper) will be different.

edit -- try removing that 430k resistor.  if you're comfortable replacing it if it doesn't help, of course. 

i re-read your post.  i'm unsure if you mean there is a steep rise in the pitch, or that there is a loop in the effect somehow.

I see. I did not create the second drawing. I got sehítséget else. And since I do not understand why it is ...

I don't think this is the way it should be wired. Try removing the most left wire from pot (on the 2nd pic). You generally want to make the resistor which sets the clock of the whole device variable. You can either replace it with pot or wire the pot paralel with timing resistor. You should probably also try larger pot capacity.

The resistance value of a kilo ohms. And because it is tied into the one 430K (second picture) I thought so little of 1k.

does it say 1Kb or 1Ka? i think thats how you tell logarithmic from linear.

I can not say what type. Three legs and rotary potentiometer. And one kilo-ohm

Which value and type of potentiometer?

I really do not understand circuit bending, but I wanted to do. And that's why I bought this cute little piano.

And I need help to change the speed.

You can do it.

Only one problem. The knob only affect the speed of sound is very fast and continuously. Can anyone tell me what went wrong? I would guess that I did not have to take what knob. And I have used something which is 1k.