Hi. I've been playing bassoon for about 2 years now, and I bought my own bassoon about 6 or 7 months ago. Recently I've begun to notice that the middle Bb (right below middle C) is really flat, and as a result I have to tighten my embouchure. However, by doing this, the note is much more likely to crack down to the lower octave for whatever reason, and the only way not to get it to crack is to open up my embouchure to the point where the Bb basically sounds like a sharp A. So now, whenever I play this note, it ALWAYS cracks down to the lower octave, and I mean ALWAYS. I have not yet found a way to combat it, even by flicking! Also, by my tightening of my embouchure, the sound of the note is TERRIBLE, and I can't do vibrato, which is a little bothersome, since it will go insanely flat. Does anyone know of any solutions to making this note crack less?

Strange that it only happens with that Bb & not the lower one as well.
What make & model of bassoon is it & did you buy it new?

Do you use the C 'octave' key for this note - either just flicking or hold it open? Maybe this vent has got blocked.

Maybe the Bb key has got bent closer to the body so the pad cannot open enough or the silencer cork betwen the touchpiece & pad key has come off giving a similar result.

Then the G &/or F keys might not be opening enough (Should be about 4.5mm from the pad surface to the tonehole rim) but this I would expect to affect the lower octave & other notes as well.

This also ought to be something your bassoon tutor can help with - might be reed or breath support problem rather than an instrument thing. I find that the Bb, B & C on all bassoons do need plenty of air support. Squeezing the reed is not the best way to go here.

Also finding a competent basoon repairer could be useful - getting this sort of thing sorted is much easier & quicker by looking at an instrument than talking on a forum. I know many woodwind repairers are not good with bassoons & those that are are thin on the ground. Ask around locally - other players, your tutor or band director.

Good luck

Thanks! I actually tried a new reed, which in some respects isn't as good as the previous one, but the Bb isn't as problematic on it.