Use this page to help decide what is needed at the output by comparing oscilation needs against power needs.

 High Power Output
Needs a transistor 
Low Power Output
Oscillating
Speaker for Alarm
Buzzer (slow pulse)
Relay (slow pulse)
Slow Flashing LEDs
Not Oscillating
Car Alarm
Relay (no pulse)
Low Power Motor
Music Chip
 
Amplified Output to a Speaker
Oscillating - at 1000 hz 
R4 = 22 000 ohms  C2 = .01 uF
Speaker for Alarm
Amplified Output to a Buzzer
Oscillating - at 1 hz. 
R4 = 2.2 M ohms  C2 = .1 uF
Buzzer with slow pulse

Relay 
Amplified Output to a Relay
Oscillating - at 1 hz. 
(relays are mechanical and less expensive ones are not built for fast action) 
R4 = 2.2 M ohms  C2 = .1 uF
Best used in 
1. Car alarms  with identifiable  slow oscillation
2. 120 volt circuit (Christmas lights) 
3. Non Oscillating toy motor circuits, instead of direct connection to pin 10. 
This option presents easy rewiring - the power to the motor is routed through the relay

The Diode is necessary.  There is a close relationship between electric current and magnetism.  As the current flows towards ground, a magnetic field expands, creating an electromagnet that closes a switch. When the electricity is turned off, the collapsing magnetic field actually pushes the current backwards.   The reversed diode across the relay helps to control the backwards surge of current and voltage pressure created by the collapsing electomagnetic field.  If it is not in place, the transistor would quickly burn out. 
Low Power motor
Not Oscillating
Electric motors use electricity and also generate electricity.
Try this with the motor outside of the circuit, if you are interested.
Connect the DMM across the motor leads and spin the shaft.  First one way, than the other. The motor also uses current and magnetic fields to create movement. 
The reversed diode across the small motor helps to control the backwards pressure of  the extra voltage created by the motor.  If it is not in place, the transistor would quickly burn out. 
A RELAY would provide much better results for any small motor
Low Power Outputs like LEDs and Music Chips
Used for low power output with oscillation.
No Oscillation
how to Remove the Oscillation: modify the basic wiring on the bread board to remove RC II. 
Connect pins 1 & 2 together and 
remove R3, R4 & C2
Used for low power output with no oscillation.  Unless of course you want to hear the first 2 seconds of the chip's tune restart over and over until RC1 times off. 
Remove the Music Chip from a Greeting Card. Don't break any wires.
  • be sure the two sides of the physical switch are connected. 
  • Examine the battery holder. 
  • Note which side is connected to ground of the battery 
  • remove the battery from the music chip.
  • Connect the ground side to pin 10.
If the sound comes out very scratchy, place 2 or 3 LEDs in line with the music chip, as shown.  They use up Voltage, dropping it down to where the music chip can use it.