Composer Friedrich Hollaender was a German Jew, like director Billy Wilder. Like Wilder, he was forced to flee Germany in the early 1930s as the Nazis came to power. Like Wilder, he moved first to Paris, and then on to America.
A lot of the most memorable music in Sabrina, though, isn't by Hollaender at all. The musical moments you're likely to remember are Audrey Hepburn seductively singing the great Edith Piaf's "La Vie En Rose" to Linus in the car, or the orchestra playing "Isn't It Romantic?" while Linus and Sabrina dance, or the snippet of "Yes, We Have No Bananas" which Linus plays for Hepburn on the boat while they're sailing.
Hollaender may not have written these tunes, but he and Wilder make excellent, evocative use of them. For example, after Sabrina and Linus listen to the novelty tune, "Yes We Have No Bananas," the song's melody pops up in Hollaender's background music when Sabrina is trying to decide whether to go up to see Linus for their last date. It's as if the song has gotten into the character's heads—just like they've gotten under each other's skin.