A genre of music commonly refereed to as "chick music" or "gay music". Bands that would fall under this category are: boy bands, girl bands, pop-country music singers/groups, etc.
It can also be used as an adjective. For instance, if a straight man is watching America's Next Top Model or listening to the Jonas Brothers, he is being homosymphonic.
In my Itunes library, I classify all of my *N Sync, Backstreet Boys and Toby Keith songs as homosymphonic under the genre setting.
My girlfriend called me homosymphonic because she walked in on me watching Project Runway.