In quite possibly the coolest ever application of the Doppler effect, KaΔa BradonjiΔ 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.
Reference
BradonjiΔ, K. (2008). Relativity of musical mood. arXiv:0807.2493v1.