What is a compliment?

Today as I got on the train a light skin dude with dreads smiled at me. To be polite I smiled back. Well this dude was one of three drummers performing on the train. After I sat down, he smiled at me again., so I smiled back and looked away to avoid any more smiling. I noticed that he and his fellow drummers were talking about me in what seemed to be a wisper. I couldn't quite make out their exact words but I knew that I was the topic of discussion. Following their mini conversation, dude with the dreads asked if I wanted to hear a song so I nodded.. then he then asked me if I wanted to hear a song about me. I shook my head...BUTTT he didn't care lol. He told his drummer friends to give him a beat. He announced to the train that I was beautiful, but not in an obnoxious way and that he was dedicating a song to me. And of course he started singing Joe Cocker's "You are so beautiful". I was embarrassed. Thank goodness he wasn't extremely loud and obnoxious because then I'd be damned. Which leads me to my point. What is a compliment? Is it a few nice words to show appreciation for somebody else? Does it matter who is giving you the compliment? I often wonder if girls appreciate an attractive guy's compliment more than an unattractive guy's compliment. I'm almost certain that a majority of women have been stopped by a guy on the street. What is your typical response? Is it any different if the guy is gorgeous? Would you go on your merry way regardless of who is stopping you? Or would you stop and enjoy conversation if the person is cute. This is the same for guys too..because I'm sure there are females out there who have voiced thier attraction for some of you in public. Would you be flattered if a girl who looked like Precious found you attractive? Or does she have to look more like Halle Berry to get you blushing. I believe that it shouldn't matter who is giving it, because a compliment is a compliment. It isn't any better if the person giving it is fat,skinny, tall, short, ugly, or attractive. Dude with the dreads wasn't the most attractive guy, but he wasn't ugly..but I still appreciated his song. Lol it made me blush.