I got to watch part of the second day of this session when it was recorded in Dallas -- "For The Last Time".
Bob fell into a coma on the first day, sending him back home to Fort Worth and cutting short the session. You'll recall, he never recovered and died shortly thereafter.
Merle Haggard drove overnight from Chicago to be there or this session and participated -- uncredited -- with some vocals and mandolin work.
I got to watch about an hour's worth from the recording booth. It was an experience I'll never forget.
Milkcow Blues -- Bob Wills & The Texas Playboys, For The last Time