Let’s get technical. If "Of Me" is an original composition (not a sample of a major label song), the copyright belongs to the producer. Distributing a free MP3 is only legal if the producer has explicitly authorized it via a or an explicit "Free Download" link.
Finding a genuine instrumental version of a song can be tricky. Often, the "instrumentals" found on free download sites are low-quality "DIY" versions created by simply lowering the vocal volume, which distorts the bass and drums. To find a studio-quality version, you need to know where to look. Of Me Instrumental Mp3 Free Download