Ok, here's the story...
Back in the 1970s there were hundreds, maybe even thousands, of drum and bugle corps around the country. Each year the VFW and AL would hold national conventions where hundreds of the corps would attend and compete. In 1972, the top corps decided to form their own organization and hold their own competitions separate from the military. That is how DCI started, and it persists today (see www.dci.org).
During that transitional periodin the late 60s/early 70s, at least two of the corps videotaped many competitions, mainly for their own instructional purposes. Luckily, they saw fit to video the first DCI championships, which today is considered a historically significant event. When those old tapes were discovered in a corps hall closet (about 80 tapes, in about 2004), it created quite a stir. Nobody knew there was footage of that founding event. I had the privilege of restoring the tapes, and hundreds of DVD sets have sold. Since then, I've created four other compilations (from other years) made from these EIAJ tapes, and they have all sold well. A second even larger batch of tapes turned up in a competing corps' closet about 2 years ago, which helped us release a set of the 1973 competition and which will doubtless lead to additional upcoming products.
I never marched in a drumcorps, but I gave drum lessons to some kids who did, and ended up enjoying attending shows. Later I got some work making recordings of the corps for their CDs and webcasts. That'se how I had the connections that led to my doing the work.
A similar huge batch of EIAJ tapes turned up, of international table tennis competition from the early 1970s, in a U.S. team members' closet. They made their way to me as well because of my longtime involvement with that activity. It's a miracle my deck still works so well after the hundreds of of tapes it has seen. It is one of the two best decks ever made - I was so lucky to find it. The only degradation has been an increasingly sluggish rewind belt that I should probably get replaced soon, if I can.
Each tape requires at least 4 hours of baking in order for it to play.
And with all that, Poita's tapes were the first Memorex I've ever seen. Most EIAJ tapes are Scotch or Sony. Frankly, I hope I don't see any more Memorex - after 8 hours of baking they were still shedding a bit.