Vibrationel energy of vibration drop?

I want to calculate the vibrational energy of vibrating water drops. To start with I assume water is inviscid.

The frequency spectrum can be found in for example Landau and Lifshitz. But I would like to know the vibrational energy of each mode.

How should I proceed? Would it be correct to say that the vibrational energy is identical to the surface tension multiplied by (largest area - smallest area)? How can this be calculated for a given frequency and amplitude? I assume quadrupole vibrations are most important.

Thanks!