Different pitched piezo's for project

[pnrule]

Hello, I'm fairly new to electronics, and this isn't a circuitry question, more about components.

Just for fun and practice I'm building a mini electronic "guitar". I'm using a circuit I found before, I believe it was a variation of a Darlington Pair, I could be wrong on the name, but it is two transistors connected in a fashion that amplifies, with two bare wires that, when touched with skin, together, complete a circuit.

Mine will have 5 of these gaps for your fingers, and I don't remember very well but I believe I can just use one pair of transistors.

I need a piezo, I believe, I'm not even sure if that's what I need, to create 5 different guitar pitches. It/they should be able to run off of a 9v battery.

Is this what I need?
Can I do it with one or do I need 5 separate?
How do I use these?

Thanks!

 

[audioguru]

You can buy an electronic organ for only $1.00 in The Dollar Store. It comes with $1.00 worth of batteries.
It has a piezo speaker and a special "organ" IC that you won't find for sale anywhere.

Or you can make the circuit with about 20 parts.

 

[pnrule]

Alright, thanks, that sounds promising. How do I get it to work though?

I have no idea how.


The original thing I did with this type of circuit just used an LED so it was + in and - out, that's it.

 

[audioguru]

A piezo speaker uses a much lower power than a "real" speaker so it is good for a simple electronic organ.
Make an oscillator with two transistors or a 555 timer/oscillator IC and the buttons on the organ select a different resistor that determines the frequency. Use a transistor or a darlington transistor at each button for skin activation.
It can play only one note at a time and the sound is a buzzing square-wave.