Initial researching.

There's over 3,300 magazines which range from many different things, from cycling to hair magazines and even food magazines.

400+ of these are music magazines. there's 40+ indie rock magazines, which is a genre that i am concidering. Some of the sub genres of this would be blues and pop. 

some of the genres of magazines that are out are:

Jazz, alternative (which is a very broad genre, it has loads of sub genres in this catorgary) R&B, rap, hip hop, drum and bass, country and metal.