I don't know how or why, but there are certain types of songs I think each of us like that span the genres to some degree but retain certain qualities. It is for this reason that I searched Napster persistently after I first heard a song called "Walk on By" played on a rural Michigan oldies station in the summer of 2000 and for this reason that my brother--who is all too familiar with my unfortunate habit of playing songs I've latched onto repetiviely for a couple of days--knew exactly which song I would like on the newest Flaming Lips CD ("The Sound of Failure," if you're interested). Dionne Warwick and the Flaming Lips do not seem similar, and I have such little knowledge of music that I could not begin to ascertain a connection between them, but in spite of this, I have a sense that there is something that connects them.
This sense is what drives a website called Pandora Internet Radio, which merely asks that you type in a treasured song or singer and goes to work finding songs whose elements are similar. A search of Marvin Gaye yielded me "These Eyes" by the Spinners, which I enjoyed. Pandora calls this process the music genome project but admits that it may not have understood exactly what you like about your original song or singer choice by allowing you to declare your dislike for a song they offer you. Like decoding a human genome, we are limited in understanding how the pieces define the whole, where in the human genome, the pieces are protein and in the music genome, they are things such as meandering melodic phrasing and acoustic sonority. If I hadn't quit piano in the sixth grade, I could probably tell you what that all means.
Still, experimenting with Pandora has allowed me to get a hold on what traits I find appealing in a song. I seem to have a penchant for orchestral arranging, major key tonality and a subtle use of vocal harmony. Alice Cooper I am not.