I know a guy in a band named Sean McCoy.  I like his name so much that when I was getting an idea for a new story with a boy MC, I decided to give him Sean's name.  

But then I thought it would kind of weird to give my character the same first and last name as an acquaintance.  (Not to mention, they both play bass.)  I was planning to keep Sean as the first name, but change the last name.  "Mc[Something Else]."  

But then I came up with the title "The Fake McCoy," and decided instead to change the character's first name.  Sean and Seth are similar enough.  Same first two letters.  Same number of letters and syllables.  And so my character has been Seth McCoy ever since.

Tonight I saw Sean McCoy at my husband's gig.  It had been a long time.   Apparently since before I started this manuscript!  I told him the title of my book.  He loved it.  Then I told him my character's name.  (I was careful not to sound like a big weirdo.)  I could tell he was really flattered.  (He even said so.  In those words!)  

He told me he'll write a song and use my name in it.  I don't think he will really, but it was sweet of him to say so.