If i buy...?

if i buy a new mouth piece for my clarinet, and have a concert two days from thursday, and play on it constanly from tomorrow to saturday will it be broken in enough?

it's chipped on the top so i do need a new one

Mouthpieces don't require "breaking in." If you replace your present mouthpiece with the same model then there should be very little adjustment time needed. If you need a new reed it will require some time to be in reliable playing condition.

Musician, composer, clarinetist, teacher.

It should be I used to play clarinet, I always hated having to replace the mouth piece and reeds, but if you work it out a little bit you should be fine

If your new mouth piece includes the reed, probably not. It's the reed(s) that need breaking in, seasoning.

Wotan

It depends. it sounds as though u practise heaps. i say don't