Who are they and what do they do? A piano tuner tries out and tunes pianos until s/he finds the precise sound. A piano tuner may go on to specialise in certain models of piano or in other instruments, such as harps, etc.
What are the activities of the job? Tries out and tunes pianos in order to find their correct sound and maintains their machinery in a good condition. S/he makes the tuning fork vibrate and then compares its sound with the sound that the cord produces; sets the tension of the cords until the sound corresponds to the one of the tuning fork; tunes the other cords according to the ones previously tuned; may repair instruments and replace the damaged or defective parts.
Where is it done and under what conditions? In the factory where the pianos are made and repaired but may also go out to private addresses. This is a craft, which is difficult to learn due to the shortage of trained professionals.
What tools/equipment do they use? Tools for repair and tuning, such as spanners, screwdrivers, etc. and a tuning fork.
What do you need to succeed? Although you need to be able to read music, high levels of educational achievement are not required. Most important of all, though, you should have perfect musical pitch or an extremely good ear for music.