HDD format issue for music files


I have an iMac with my music files stored on an external hard drive.  I got a new hard drive from WD and formatted it for Mac OS and copied some of my music onto it.  I gave it to a friend who has a PC and he connected the hard drive to his PC and sees no files.  Should I have formatted the drive for a PC rather than a Mac?  Thanks. 

whitestix

Format the drive on your MAC as exFAT and add your files on the MAC.  They will be viewable on a PC.

Well, much appreciated, I am sure that your answer to my plight.  Thanks for the taking time to reply. ;-)