Re: A6 fingering for Ravel Sonatine for oboe and piano
Notes from a6 and above are generally not reliable. Period. Even the top players say this, and have trouble up there.
You might try a shorter tip, and varying the thickness to find what works for you.
In a way, I feel it is unfortunate that composers have burdened oboists with these super high notes.
One fingering is 3rd octave + 2nd octave + half hole===yes, all three, then B0X/00X, thus half hole, g key, d key.
Take more reed into your mouth, USE LESS AIR---think how "short" that pitch is in acoustical terms.
Hear it, think it, before you play.