The original Blue Note was produced by the Meteor at high speed.
The whistle of a Vampire is not a Blue Note.
The combination of engine and airframe noise, particularly that produced by the fuselage gun ports, made a distinctive note which was instantly recognisable.
It is not a noise that I find easy to describe except to say that when you have heard it you won't forget or confuse it with anything else.
The Hunter does produce a distinctive noise but it is not the same as that made by the Meteor.