Hi, i am in Tau Beta Sigma, the sister organization to Kappa Kappa Psi. I would allow a Brother to post the distinction between the two orgs, but it seems that none of them frequent GC.
Kappa Kappa Psi is a National Honorary Band Fraternity. Being an organization which serves the band, university department of music, and the community of music at large. the webpage for our national headquarters is
http://www.kkytbs.org
Someone asked about the org being coed. Since the nature of membership is
honorary we are obligated under Title IX to extend membership to qualified persons regardless of gender. So you may see a man in Tau Beta Sigma or a woman in Kappa Kappa Psi. please don't confuse my statement about extending membership - this doesn't mean that everyone who wants in gets in, but we are not social orgs that can limit membership to a single sex.
You also pointed out that some members have brands, step, do a call and have hand signs. It's all in brotherly (and sisterly) love. Some chapters have a rich tradition of stepping, others don't...
And being an honorary fraternity allows members of Kappa Kappa Psi and Tau Beta Sigma to pursue membership in NPC/NPHC orgs as well. You may have a person in Kappa Kappa Psi and Kappa Alpha Psi (or any other org, you get the picture). it happens.
And as far as it being a "marching band" frat - that is not the case. Some universities do not have marching band but they still have Kappa Kappa Psi and/or Tau Beta Sigma. we are of service to the Director of Music at the university.
Hope this info helps.