I'm just a regular slob so this concept fascinates me. There are bars, restaurants, hotels which change music according to who is walking in? Where and who? I would think that there are very few people who actually have their own "theme song".
A long time ago in a galaxy far far away I was for a short time a piano player in some of the bars in Cleveland and Columbus Ohio and there were rules for the crowd. Such as when the gray haired clientele was in the bar/club you stuck to waltzes and big band era stuff. Where as the Narrow Tie crowd being young career types (it was the early 80s) out for some warm up activity before heading to the hot spots you played lots of Billy Joel etc.
And if a regular walked in (wanting his tonic and gin [/Piano Man]} You would do well to break into the Song He requested most. Cause he'd get a drink from the Bar and put Bread in your Jar, And say, "Man, what are you doin' here?" (With Apologies to Mr. Joel)
Its all about connecting with the customers and good Bar Musicians and Bar Managers have known such for years.
For instance You've got a choice between a really good local Bar Band who can play anything you want but the people that tend to appreciate them are older and don't stay as late and don't spend much on booze. OR you can get the New Local band that barely can stay on the beat let alone in tune but they are loud AND all the girls in the area are totally in love with the lead singer which brings in the hot chicks which brings in the guys who buy lots of drinks and hang around all night trying to get laid.
Just a matter of Bar economics.