You can use any audio material that you own, either physically or digitally. You must have purchased a copy of the audio material. You cannot use bootleg copies, as per the DMCA agreements. There must be only one song per Track so that the metadata can be accurately recorded.
The tracks must be in an .MP3 or .M4A format. For example, you can create .MP3s from CDs or records that you own, or you can use .MP3s that you’ve purchased off digital marketplaces like iTunes, Amazon music etc. You can read more about how to convert audio to .MP3 formats here.
You can also use audio recordings of voice or music that you’ve created yourself. There are endless possibilities, but all tracks must be in .MP3 or .M4A formats if you intend to use them with Live365.