The "morning flute/ morgenflöte" is a light depended instrument, which is best played in the morning.

It uses photocells, LDRs(light depended resistors) implemented in the cardboard tube attached to 555 timers on the breadboard.

There is already a lot of light depended instruments prob. all based on similar circuits and the same principle, when the LDR gets a lot of light the resistance decreases and the timing capacitor charges quicker which increases the frequency. When it´s dark the resistance of the LDR gets high and the timing capacitor charges very slowly, you will hear no tone only a series of clicks(depending on capacitor and resistor combination).

I made 2 kinds of flutes, one is more precise with just a few holes, which you play like a "normal" flute and a cracy push-pull and roll one with 386? holes.

Let´s build it - no soldering skills needed...

Step 1: Materials

mailing tubes /cardboard tubes with lid

if you want to make a handy flute you prob. have to shorten the tube

saw, sandpaper

for the holes of the flute use

hammer, big nail

to make the hole bigger use

screwdriver and or scissors

to fix the lid and to cover it

duck tape

drilling machine(saves time, when you want to have a lot of holes...)

Optional materials
if you want to make the flute look more exciting

colored foil, holographic paper

the effect on the LDR is very low or zero

important: design the flute as you want, but if you have just a few holes dont put them to close to the bottom where the LDR sits, when the closest hole is open you will hardly hear the rest of the holes. I tried different kind of flutes a more precise one with just 6 holes and a cracy push pull and roll one with 383? holes.

Step 2: Parts

breadboard

9V battery

alligator clips

jumper wire

(8 Ω )speaker

0.1μF (100nF) 25V Electrolytic Capacitor

photocell, LDR(or CdS)

resistors (1kΩ to 1MΩ, best results for this circuit 10kΩ)

555 timer

LED(to control)

0.01μF (10nF) Ceramic Capacitor

Step 3: Circuit

connect the 8 pins of the 555 timer as an astable multivibrator

like this

Pin 1 to GND

Pin 1 via ceramic capacitor to Pin 2

Pin 2 to Pin 6

Pin 3 to (anode of)LED (cathode) to resistor 1 kΩ to GND (to see if the circuit is working)

Pin 3 to (anode of) capacitor (cathode) to speaker (2 pins, other one) to GND

Pin 4 to Vcc(+)

(opt. Pin 5 via ceramic capacitor to GND)

Pin 6 (connected to Pin 2) to LDR (1 leg)

Pin 7 to LDR (2 leg)

Pin 7 to resistor 10 kΩ to Pin 8

Pin 8 to Vcc(+)

connect 9V battery to the board

there should be some sound and and a blinking LED

Step 4: Attach the Flute

when you put the LDR in the flute you need to take care of the 2 legs of LDR, they shouldnt touch each other.

just build a little bracket to avoid this, put on the lid and its very steady now, you can also extend the alligator clips with wire to move a bit, when you play.

Step 5: Go Crazy

1. add another 555 to the board, build just the same circuit and maybe a third one...

2. put the output Pin 3 from your 2nd 555 astable circuit next to output Pin 3 of the 1st 555 -->to (anode of) capacitor...speaker, (you should here 2 different sounds, even its the same circuit, because 2 flutes shouldnt sound the same)

3. or you can also put the output Pin 3 from your 1st 555 astable circuit to Pin 5 of your 2nd 555 astable circuit, then the first circuit modulates the second, and generates different frequencies

4. play around, try different resistors, a poti... and have fun!