In quite possibly the coolest ever application of the Doppler effect, Kaća Bradonjić has shown what velocity you ought to move in to hear, e.g., a major (triad) chord as a minor chord and vice versa, if the three notes are played from three different locations. (I shan’t pretend to have waded through the maths.)
Bradonjić, K. (2008). Relativity of musical mood. arXiv:0807.2493v1.