How the heck do you trill from A-flat to B-flat? My band teacher told me you lift up the second finger on the left hand... but that sounds totally wrong. I'm messing with my oboe now... and that's the A-flat to B-natural trill. Help please!

Your band teacher is correct. The proper trill for A-flat to B-flat is to lift the second finger of the left hand, however it sounds to me that you are playing on an oboe that does not have full trill groupings. Most oboes have what appears to be a lever that holds down the A key, [second finger left hand key] when you apply the A-Flat key. That lever is what helps play an A-flat to B-flat trill. You may have to fake it and have to use full fingerings. Try keeping your A-flat key down while you lift your left third finger and put down your right hand index finger. It will take some coordination.

yes, that's the easiest way. however there is another one. finger A flat and then press down the key above the right A flat

The key above the right hand A flat key is for A-flat or G-sharp to A natural trill. It closes the third finger [G] key so the interval tight and close. If you try to trill using that fingering you will not have a trill of one complete diatonic step.

oh really? lol. that's what my book said.