A 555 produces frequencies, not musical notes. To produce accurate musical notes then each resistor must be trimmed with a trimmer resistor.

Many years ago there were ICs that accurately produced an entire musical scale.
I doubt if one is available today. Maybe a microcontroller can be programmed to produce the scale.

 

The answer is yes, it would be a keyboard instrument. After I drew I realized there is a better way, which I will draw soon. Right now I'm enjoying Christmas (I snuck away to get online).

 

Bad news. I gave the project to a friend and it all of a sudden stopped working. I got it back from him. When I turned it on, the LED lit up but it made no sound. Due to an error when building, only 1 IC chip was in a socket (the pitch circuit). I replaced the pitch IC and the pitch circuit started working. Because the pulse IC was directly soldered to the board, I am not certain that it was faulty but I am thinking that it is.

Is there an error in my circuit that would cause the IC's to fail over time?

 

Best guess, static electricity. The electronics is open to the world.

You can replace the 555. I would put everything in a tin, you should have some left over from Christmas.

ElectroStatic Discharge

I'll also go back and review your schematics.

 

Looking at it it is possible R1 and R4 are too low a value, what did you use?

Suggestion, the second 555. Leave pin8 connected full time to the power supply (9V) and pin 4 is the input.

Where is the speaker in this scheme?

 

If the battery was connected backwards, even for less than 1 second then the ICs are destroyed. Adding as diode in series with one of the battery wires prevents destruction.

 

R4 was 2.2k and R1 was 1k. The speaker is not in the schematic. It has an output jack that connects to an amplifier or speaker via quarter inch cable.