Replying to Whats a good way to back up my external harddrive ?

so i keep getting this message that tells me to reformat my ext hard drive which sorta scares me ... i'm scared it might crash or i might just randomly loose all my stuff which is like 55 gigs of music which would crush me ...

what should i do ?

i was thinking of possibly just getting all of the stuff i really wanted and putting it in a zip. or a rar. file and maybe putting those files on a thumb drive if they can fit after being compressed ..... please help