This is a website I discovered about a week ago. It basically generates tracks based on some music category (Folk/Piano/Pop/Cinematic/…).
It is called Jukedeck
Alright, the music is not perfect, but if you have got no audio or a guy who can make sound effects as well as one or two background music songs during the gamejam period, you can just generate a couple of songs and choose the best sounding one :). It gives you X free downloads per month, but it also got a premium plan. (Disclaimer: I did not get paid to make this post, neither do I want to advertise).
Here are some samples that I generated(Even if you choose the same song type , its different every time!):
^These were made in like 5 minutes.
Happy music making and game jamming.