  An experimental investigation of nonlinear interactions between shear
Alfv\'{e}n waves in a laboratory plasma is presented. Two Alfv\'{e}n waves,
generated by a resonant cavity, are observed to beat together, driving a low
frequency nonlinear psuedo-mode at the beat frequency. The psuedo-mode then
scatters the Alfv\'{e}n waves, generating a series of sidebands. The observed
interaction is very strong, with the normalized amplitude of the driven
psuedo-mode comparable to the normalized magnetic field amplitude ($\delta
B/B$) of the interacting Alfv\'{e}n waves.
