Both the 1966 original Broadway cast (Sony/Columbia Broadway masterworks) and the 1998 Broadway revival cast (RCA Victor) are well worth having. If you can only get one, start with the original which is about half the price of revival disc.
The original features Joel Grey (MC), Lotte Lenya (Faulein Schneider) and Jack Gilford (Herr Schultz) who are all unbeatable in their roles. (Lenya was the widow of Kurt Weill, and with him they escaped Naz Germany to come to America.) The Sally (Jill Haworth) and Cliff (Bert Convy) are the weakest links on this disc. The score is the way it was heard on opening night in 1966: Includes "Why Should I Wake Up", "Meeksite" and the original Money song "Sitting Pretty." It also makes some changes for the purposes of recording. "The Telephone Song" is done at double the speed it was performed in the theatre to recreate for the ears alone the excitement of Ron Field's choreography. Also in the finale, album producer Goddard Lieberson took out the spoken dialogue and substituted short reprises of key songs instead..so Schneider sings a few bars of "So What" and Shultz sings a few bars of "Meeskite." (In the script they spoke lines they had spoken earlier in the show.)
The 1998 revival cast gains in Natasha Richardson's Sally and John Benjamin Hickey's Cliff. Alan Cumming is sensational as the MC (or Emcee). It adds "Mein Herr" (good), "Maybe This Time" (a mistake! All wrong for Sally. Does she really think of herself as Lady Peaceful???), "I Don't Care Much" (great song but a needless addition at that point in the show), and uses the movie's "Money Money" (an improvement on the original.) There's also a bit more dialogue on the CD, and it captures the new production with dazzling theatricality.
The movie soundtrack is useless as a reference for the stage show. The movie script uses the play I AM A CAMARA as its source and inserts the CABARET songs into that. The sub-plot with Schneider and Shultz is gone (Schneider makes only a fleeting apperance in the film); Sally is American and 'Brian' (as the Cliff character is known in the film) is British and does not sing - almost all the songs are done by Sally and/or the Emcee. The movie retains only 5 songs from the stage score (3 others are used as background music) addding "Mein Herr", "Maybe This Time" and "Mopney Money." It is a fantastic film, but it bears little resemblence to CABARET as seen on stage.
The two London cast recordings are both disappointing. Judi Dench was Sally in the original London Production (on Sony West end - out-of-print) and Lila Kedrova (ZORBA) was Schneider but none of the cast compare with their Broadway counterparts. A 1986 London revival featuring Wayne Sleep (First Night) has reduced orchestrations and weak cast. Skip it.
An elaborate 2 CD set (JAY/TER) has the complete original Broadway score plus an appendix of most of the other songs. Judi Dench is back, this time as Schneider. It documents the exact tempos used on stage (which robs the set of the vitality Columbia's 1966 OCR has) but it is a fine reference recording.
Cast albums are NOT "soundtracks."
Live theatre does not use a "soundtrack." If it did, it wouldn't be live theatre!
I host a weekly one-hour radio program featuring cast album selections as well as songs by cabaret, jazz and theatre artists. The program, FRONT ROW CENTRE is heard Sundays 9 to 10 am and also Saturdays from 8 to 9 am (eastern times) on www.proudfm.com