It's well known that Bob Dylan and George Harrison went into a studio in NYC in May of 1970. It was supposed to be a secret, but apparently Rolling Stone printed a report about the session almost immediately after it happened. I've been going through the Dylan "Bootleg Series" compact discs, trying to figure out what tracks came from this session. Apparently it was one session and most sources I'm finding are listing the date as May 1, 1970. I found one web site that listed a huge amount of chronological information about every Dylan recording and it listed a fairly long list of tracks that were done that day. Some of them false starts, and re-takes. I'm fuzzy on the exact number, but this site listed like 30+ tracks... many of them just jams on old songs. At the bottom of the list, it gave pointers to the places where some of the songs were officially released. And it also provided some pointers to what are clearly bootlegs. Basically, the official sources are "New Morning" album, the new Bootleg Series release (Vol 10?) that just came out (Another Self Portrait), the first Bootleg Series release, and maybe one other place that I'm forgetting (Biograph?). But the one that stunned me is they were listing a fairly large chunk of the days' output as having come out on something they were calling the "Columbia Recording Studios Reference Recordings" (which seems to be listed elsewhere as the "CBS Studio Reference Recording Archives".) I know those specific tracks have been bootlegged - but the notion that they were also OFFICIALLY released is news to me. Is that just a code word for a test pressing or acetate ? I wouldn't go so far as to call that an "official release".... unless they are just assuming "official" means legal (for that specific acetate or test pressing)... but I would argue that "release" means it was released to the PUBLIC - not just a copy or two intended for a limited audience. I'd like to think there is an on-line "archive" that is accessible to the public - but I don't think that's what they were talking about. I'm hoping there's some 10 CD box set called "Columbia Recording Studios Reference Recordings" but I'm extremely skeptical that something of that nature slipped out without me noticing.