Open iTunes. Click File, Add File to Library, then navigate to where your new music file is located. Then add/import.
I recently bought a Digitech Model GE-4059 turntable player with USB port and find the accompanying instruction manual is of little help in commissioning the unit. I "save as" an iTunes project but cannot find the recorded music in my iTunes library.
When I click on "Recent Files" in Audacity, the file name I nominated ending in iTunes appears and I can play the track. I need to get technical help from someone who is conversant with the technology and understands why I'm stuck.