I assume that everyone has one. But perhaps you call it something else. Let me illustrate: one of my best guy friends in high school (I won't out him, but Qwanty can probably guess) had this thing about being touched on his neck. He had a very immediate and rather pronounced response to being touched there. (Although I'm not sure how exactly it manifested itself, and I don't think I want to think about it much.) But he would literally jump up and thunder, "DON'T TOUCH ME THERE! YOU KNOW NOT TO TOUCH ME THERE!" when someone did it. Bear in mind that, in those days, I was often in situations that necessitated me sitting behind him (on bleachers at football or basketball games, in the backseat of the car while he was driving), and I did know better than to touch him there, but it was just so tempting . . . Anyway, it was a sweet spot.
Or, if another illustration is needed: you might think about when you scratch an itch exactly at its origin. You have that sense of relief and pleasure all at once. It's a sweet spot.
There is certain music that scratches the itch, or hits the sweet spot, aurally. These are sounds that sort of cause a wave of pleasure (and get your mind out of the gutter--this is not a sexual kind of pleasure. It is altogether different.) and a sort of feeling of goodwill. It's music that sounds like it is perfectly scratching some invisible itch in your ear--an itch you didn't even know you had.
I get this same feeling when I hear:
Any of Jeff Buckley's recordings
Post-Soundgarden Chris Cornell
When Michael Stipe sings backing vocals (like on the Indigo Girls's "Kid Fears" or "Tried to be True" or on the live recording of "Love is All Around" from REM's Unplugged episode)
Ditto for Natalie Merchant (as on "Way Over Yonder . . . " from the first Mermaid Ave. album)
Also, Thom Yorke (on PJ Harvey's "The Mess We're In"--a song I absolutely LOVE, or on some Bjork tracks)
There are basically two categories here. The first is guys who have voices like "pissed off angels" (Kiedis, Cornell, Buckley).* They all have sort of gorgeous and smooth voices with an edge.
*I can't take credit for the "voice of a pissed off angel" thing. This actually comes from some guy who has a Clockhammer fan site and used that phrase to describe Byron's voice. I actually don't know if I agree with it being applied to the Byronic Hero--although it's hard to say, since I never heard him sing live.