- The confusion of on the dating of the August 21 tape is made clear; the show was scheduled for August 20, but actually played the on August 21, accounting for the confusing dating on Bear's tape of the show (which he correctly identified as August 21).
- The Aqua Theatre show seems to have been the first joint performance of the Dead and the New Riders, certainly the first "proof of concept" out of town performance
- On the night of the 20th, the Dead, and possibly the Riders, played a bar on West 15th Street in Seattle. Update: the bar was apparently El Roach, at 5419 Ballard Avenue NW, in the suburb of Ballard (just Southwest of Seattle proper).
There is not actually a West 15th Street in Seattle (the streets are on different axes), so I have to assume the unnamed bar was either around 15th Ave NW a few miles West of Green Lake or else on 15th Avenue, near Downtown and Seattle University, about 7 miles South. The bar must have had a stage and some facility for power, and thus certainly must have regularly presented music, so it couldn't be completely unknown. Any suggestions as to the mystery club are certainly welcome (update: El Roach was just 2.8 miles from the Aqua Theatre, not far from 15th Ave NW).
Green Lake Aqua Theatre, Seattle, WA
The Aqua Theatre on Seattle's Green Lake was built in 1950 to accommodate a Water Ballet at the Seattle Summer Sea Fest. The stage of the Theatre was actually on the shores of Green Lake, with a huge reflecting pool in front of the stage. The arena initially seated about 5,200, later expanded to 5,582. Various visiting shows and musical performers appeared at the Aqua Theatre over the years. Some high profile events were scheduled there for the 1962 Seattle World's Fair, but there were problems due to the unpredictable Summer Weather, and the venue fell out of favor with promoters. By the late 1960s it was somewhat of a white elephant for the city of Seattle, but it was still used sometimes by rock music promoters.
The most famous rock show at the Aqua Theatre was on May 11, 1969, when Led Zeppelin performed there (with Three Dog Night as the opening act). Led Zeppelin sites have some great photos of the venue and recollections of the concert. This photo in particular gives an interesting perspective on bands performing at this unique venue (note how relatively little equipment Led Zeppelin had in 1969).
The Grateful Dead performance on August 21, 1969 apparently caused some concern about the grandstands. They were inspected, and structural flaws were found that caused the venue to be closed, making the Grateful Dead performance the last concert at the venue (whatever Led Zeppelin had not destroyed, the Dead seemed to have finished off). The venue was torn down in 1970. Parts of the grandstand still remain, and a historic marker identifies the site at 5900 W. Green Lake Way N.