  The loop variable approach used earlier to obtain free equations of motion
for the massive modes of the open string, is generalized to include interaction
terms. These terms, which are polynomial, involve only modes of strictly lower
mass. Considerations based on operator product expansions suggest that these
equations are particular truncations of the full string equations. The method
involves broadening the loop to a band of finite thickness that describes all
the different interacting strings. Interestingly, in terms of these variables,
the theory appears non-interacting.
