Five designers. Five years. A body of work that constitutes one of the strangest and most consequential episodes in American poster history. Wes Wilson, Victor Moscoso, Alton Kelley, Stanley Mouse, and Bonnie MacLean — working largely for promoters Bill Graham at the Fillmore and Chet Helms at the Avalon Ballroom — developed a visual language so specific to its moment that it has never been successfully separated from it. Every subsequent attempt to use the style without the context reads as pastiche.