Recorders are fairly easy to play; much easier than side-blown flutes. They are relatively cheap instruments to buy, but if you want some DIY fun, here's how to make one out of PVC pipe.
To hear how it sounds, listen to the .mp3 audio file in the last step.
Step 1: The Parts of the Recorder
The recorder is composed of three parts; the mouthpiece, the body with the fingering holes, and the standard connector which joins the mouthpiece and the body.
The spacing and size of the holes in the body are copied from a store-bought plastic recorder.
The mouthpiece is composed of concentric layers of different size pipe. The pipe diameters are: 1/2" CPVC (smallest diameter used for hot water), 1/2" PVC (the layer around it with a section removed to create an air channel), and 3/4" PVC (to cap the top of the air channel).
The air channel conducts the air you blow to a sounding hole. A wedge shape at the hole interrupts the air flow and creates vibration and sound.
The fingering holes in the body modify the pitch of the sound by creating different amounts of resistance to the air passing through the pipe. Opening all the holes lets air escape with less resistance by the easiest route, through the first holes. Closing all the holes creates a longer column of air inside the body, and more resistance, which results in lower notes.