How are wall vibrations of organ pipes influenced by material choice and tooling methods ? Six groups of three equally made diapason organ pipes (tuned to C4 at 260 Hz) fabricated out of two different alloys and with three tooling methods are investigated. All experiments are performed with the pipes mounted in an experimental organ. Results from the following experiments are compared: Modes of vibration for external sinusoidal excitation of the walls, so called free structural eigenmodes, are measured using TV holography, a non contact, optical, full field measuring method. These measurements are performed both before and after voicing of the pipes. The pipes are externally excited, sinusoidal, at the fundamental frequency and five higher harmonics (n*260 Hz where n = 1, 2, ..., 6) of the blown pipe. Forced structural modes of vibration at those frequencies are measured, again using TV holography. Structural modes of vibration of the blown pipes are measured. This time shearography is used, another optical non contact measuring method.The results show that structural vibrations are affected by the choice of material and tooling; a pipe with higher tin contents have higher eigenfrequencies. It is also shown that the voicing process selects certain modes of vibration in the pipes.