About recorders: having your fingers are on the right holes doesn't guarantee that the note you will play is in tune. Slight changes in your breath, in the shape of your mouth, and the distance of your thumb from the thumb hole can change the pitch.

Such things apply to many instruments, not just to recorders.

Fortunately, there is a simple answer to this. I quote:

"Ninety percent of intonation is attention."

It is amazing what your body (fingers, mouth, breath) and your hearing can accomplish by listening to the rest of the group. Just tell your left brain (the part that thinks it has to be the boss all the time)to butt out and let the other parts of your body do it. Then listen to the group, listen to yourself and ask, 'Does this sound right?' Fix it if it doesn't.

One day I got fed up with our perpetually flat flute players. I told them we'd play a song again, and this time they 'should listen to Patty.' Patty being our guitarist. They had never done that before. There was a real improvement. It wasn't amazing; they didn't turn into James Galways before our eyes, but there still was a noticeable improvement in their playing.

Two other things about recorders: 1. on some notes, esp high ones, the fingering that the maker specifies may not be the best one. Check out the options from a fingering chart and experiment.

2. On all recorders, the note that takes just the index finger is very, very touchy, with a strong tendency to go sharp. On a soprano this is a D. Watch the distance of your thumb from the hole. Add a finger, starting at the bottom of the recorder until it's not shrieky.

I try to avoid high D's on sopranos.

It is certainly not true that a recorder (or a whistle) is merely a diatonic instrument.