One of the fascinating series of discussions at the National Performing Arts Convention have hovered around what constitutes a ''national performing arts community.'' Given the convening of this event by national service organizations for formally organized, primarily nonprofit cultural organizations, the bias in the perspectives is probably obvious: the ''performing arts community'' includes nonprofit and public institutions, artists, audiences, and supporters in artistic disciplines we know.

But every now and then, during a caucus roundtable conversation or in a workshop session, somebody raises the question: is the performing arts community really only that? What about commercial organizations that present live performances -- promoters, stadium shows, nightclubs? What about informal community groups that lack an organizing structure and often lack a budget? What about forms of performing expression not generally organized under a nonprofit or public structure -- rock bands, folk groups, cultural heritage centers, urban poetry slams? What about individual artists who spend the bulk of their days as piano teachers, high school music teachers, and critics or scholars of music or dance or social expression? What about the phalanx of popular reality shows built upon singing, or dancing, or acting -- American Idol, So You Think You Can Dance?, Step It Up and Dance, or even Inside the Actors Studio?

It may sound like an endlessly complex and nuanced exercise, but defining who's in and who's out of a ''community'' is often a necessary first step of how that community might organize and mobilize to advance its common goals. Without that definition, we can easily miss many powerful and persuasive partners in our efforts. Or we can dull the focus of our strategies and tactics for collective action.

We're not likely to resolve the question anytime soon. But it's glorious to watch as 3500 people make the effort.