Mystery Train, the old, was recorded at Sun Studios on 11 July 1955 and Tiger man was the new, never properly recorded in the studio by Elvis but is perhaps synonomous with The NBC Special where it was first heard during the sit down segment although not included in the original TV show. The song itself from that sit down show at 8PM on 27 June 1968 was released on album 'Elvis Sings Flaming Star' in 1968, on the RCA Camden budget label!!
At the beginning of the first day of recordings in Nashville on 4 June 1970 an informal jam of this medley was recorded by Felton Jarvis and this was officially released on the FTD album 'The Nashville Marathon' in 2002.
Despite being an ever present throughout Elvis' inaugural Vegas engagement it was dropped completely for the January/February 1970 run but was reintroduced for opening night of the next stint on 10 August 1970 and that version would be played over the opening credits of the original TTWII 1970 movie. The medley would come and go on a show by show basis throughout the 70's and would latterly be used as an alternative penultimate number in the show instead of the usual 'Funny How Time Slips Away'.
This version filmed at the beginning of the 12 August 1970 Midnight Show was also appeared in the original movie but only the 'Tiger Man' portion was used as it linked a fan club convention in Luxembourg with the second live section of the movie.
Only two songs into this show and Elvis is already in the groove! Just watch his face closely in Tiger Man as he pushes the song along and that breathtaking 'whoo' just before an amazing guitar solo by James Burton plus if you listen closely you can hear cheers of appreciation from the audience during the song!!