"The 20th Century Fox Mambo" is an original song introduced in the second episode of the first season of the musical TV series Smash, entitled "The Callback".
In "The Callback" episode, Karen Cartwright (Katharine McPhee) needs to give a dance audition for the producing team as part of trying to get the role of Marilyn in Bombshell.
"[2] Noel Murray of The AV Club says "after Karen gives her big dance audition to “The 20th Century Fox Mambo”...the Marilyn creative team indicates that she nailed it".
He compares the makeover aspect of the song to Evita's "Rainbow High", and adds that sometimes the song was as "lyrically strained" Tim Rice's work, citing: "accenting the word 'the' to keep the rhythm, rhyming obsessively and ostentatiously, strenuously saying nothing and saying it repeatedly, and contracting words to cheat metrical death (e.g., fac'try for factory)", as ways in which "this number trades coquettishly in lyrical hedges that really push [his] buttons".
[3] An Allmusic review by Heather Phares notes that "a Chicago-style brassiness dominates "The 20th Century Fox Mambo" and "Let's Be Bad," both of which sound the most like genuine show tunes".