"Never Give All the Heart" is an original song introduced in the first episode of the first season of the musical TV series Smash, titled "Pilot".
Ivy Lynn's version of "Never Give All the Heart" was performed in the show as demo track that was recorded for Tom and Julia as they pondered actually attempting the Marilyn musical.
Cartright's "exquisitely and evocatively emotional 'Never Give All The Heart' [which gave] way to a grand diva entrance for the highly anticipated debut of movie star Rebecca Duvall (guest star Uma Thurman), who took the applause...as she walked into the room" was described by Pat Cerasaro of broadwayworld.com as "a nod to Michael Bennett’s heart-stopping coup de theatre Act One Finale for DREAMGIRLS".
He explains that cruel realism of scene by saying, "[the song] set up the sad fact that just as she was starting to get good, in walks some miscast movie star.
Listen again, trust me.The song is in the key of Bb Major, ranges from F#3-C5, and the tempo is described on the sheet music as being "ballad style, [sung] freely with expression" (q = 100).