The background music played by fast food restaurants and five-star hotels in society is different as follows:

1. Music style: The background music of fast food restaurants is usually pop music, because this kind of music has a wide audience and can attract customers of different ages and preferences. Five-star hotels usually play more elegant music, such as classical music or light music, to create a more noble and formal atmosphere.

2. Music rhythm: The music rhythm of fast food restaurants is usually faster to match the fast-paced catering service. This kind of music can make customers feel relaxed and happy atmosphere while enjoying delicious food. In contrast, the music rhythm of five-star hotels is relatively gentle, focusing on creating an elegant and quiet atmosphere, so that customers can feel more comfortable and relaxed during the dining process.

3. Volume control: The background music of fast food restaurants is usually loud to drown out the noisy ambient sound and make it easier for customers to hear the music. At the same time, this volume control can also create a more lively atmosphere. However, the music volume of five-star hotels is usually low to avoid interference with customers' conversation and provide a more comfortable dining environment.

4. Time and regularity of music playing: The background music of fast food restaurants is usually played continuously during business hours to attract customers and maintain a pleasant atmosphere during the whole meal. However, the music playing time and rules of five-star hotels are more flexible, and may be adjusted according to customers' needs and meal time.