An American record producer helps a French pop singer who is a one hit wonder and faded into obscurity by helping her to come to America and gain success.

Consider the following:
What’s the producer's arc? Looking for more than just a pack mule for this singer.
Consider strengthening the America or Bust premise by finding a compelling reason why a French singer would risk whatever to seek fortune in American.
Examples:
“A once-famous OR down-and-out record producer [comeback GOAL]…” “… French one-hit-wonder …”.
Both parties can find inspiration in each other for their comeback/seek fortune goal.

This is your story, hope this helps, take care.