So I just had music files on my USB flash memory Drive and inserted into my MacBook to listen to them. But after rejected the USB flash memory drive, all the music remained on my Mac iTunes library and listening to them as I type.... I did not really want the music on there, how did they got there ? and how can I get rid of them clean and clear ? All I wanted to do was to listen to what was on the USB flash memory drive. I did not mean to copy/import them on to my mac.