The combined effect of impedance and higher order chromaticity can act on the beam in a nontrivial manner which can cause a tune shift which depends on the relative momenta w.r.t. the "on momentum" particle (∆p/p). Experimentally, this tune shift affects the measurement of the linear chromaticity which is traditionally measured with a change of ∆p/p. The theory behind this effect will be derived in this paper. Computer simulations and experimental data from the Tevatron will be used to support the theory.