needling technique

[Phil Bondi]

André,

I will concur with the esteemed colleague from the Great City Of 
Jacksonville, Fl. This method, seemingly to be ineffective, can be quite 
beneficial to concrete trying to imitate a piano hammer.  .. just a 
'pinch' under the crown can bring a bucket of broken glass back down to 
a more pleasant listening level.

Phil Bondi(Fl)