Radiohead's Thom Yorke is probably the most interesting singer in rock, and has been for some time, in my opinion. His work ethic is what makes him so; the fact that he has spent so much time writing music using piano, guitar and voice is one factor that gives him a sound that's sensitive and subtle, but also very powerful. It's also clear that he's learned a lot from great singers of the past and present. In an earlier post, I mentioned how he's indebted to John Lydon, a fact that's particularly evident on the more manic material (like "Bodysnatchers", for example), and Neil Young is also a big influence, and there are several great videos on YouTube of him and Radiohead doing Young songs. Here's a version of "Tell Me Why" that is terrific (despite the crowd noise): http://www.youtube.com/watch?v=kHIJcx9EB94. Another singer that can be heard in Yorke is Bryan Ferry, and the version of "2HB" from the soundtrack of Velvet Goldmine, a 1998 film, is quite surprising for Yorke's uncanny impersonation of the Roxy frontman. It's definitely worth a listen: http://www.youtube.com/watch?v=hxcDwzsx8OQ