XLIIs presents collections of Grateful Dead live recordings on loan from collectors around the world. Every three months, four new collections arrive — each one assembled by a different collector around a single idea. Every show comes with a historical write-up. Every collectors original cassettes and J-card inserts are photographed and available in the app. This season: 171 shows from 1969 to 1980, on loan from collectors in Wales, Hungary, Romania, and Estonia.