What is the natural harmonic frequency for Trinitrotoluene?

The natural frequency of a structure depends on both the material
properties (specifically stiffness or modulus of elasticity) and the
geometry of the structure.

For a simple beam pulled in tension, the frequency is given by f = [1
/ (2*pi)] * sqrt[k/m]
Where m is the mass of the beam and
k is the spring constant that is approximately the cross-sectional
area of the structure * the modulus of elasticity.

Trinitrotoluene (TNT) is generally prepared with a polymer binder, and
therefore the exact modulus of elasticity will depend on the entire
matrix.

Ballpark figures for the modulus of elasticity of a TNT mix is
probably 5-15 thousand psi.

http://en.wikipedia.org/wiki/Trinitrotoluene has some good information on TNT

If you're trying to create resonance to get a nice BOOM, let me know
how it goes...  It's an interesting idea, but I'm pretty sure heat is
required... I don't think you can simply shake it and get the same
effect.