Coherent control of occupation numbers in quantum mechanical multilevel systems is widely studied driven by its application in lasers and its prospects for quantum computational elements. Here the authors present a nanoelectromechanical resonator equivalent to the coherent control of a quantum mechanical two level system. The distinct eigenmodes of a nanomechanical beam resonator represent the two levels whose amplitude mode occupation numbers are controlled by a frequency matched acoustic excitation, mediated by a pulsed surface acoustic wave. They show that similar to quantum mechanical systems it is possible to transfer occupation numbers from one mode to another by matched acoustic pulses. (c) 2007 American Institute of Physics.