Dream Theater, Rush, Trivium, Opeth
I like each of these bands since I am a progressive metal singer. KTVA has helped me a lot with singing in these styles even though Ken hasn't posted videos on how to sing like Geddy Lee, James Labrie, Matt Heafy, or Lars Mikael Akerfeldt. It would be cool for Ken Tamplin and any other singers to try these styles and do some covers. These guys have some good talent along with Led Zeppelin and other influences in metal music. "Pull Me under" by Dream Theater is a pretty hard tune to learn. I could easily sing the first verse and pre-chorus really well but the other parts of the song like the second and third verses along with the chorus are hard to sing. "Red barchetta" is easy for a countertenor to sing but it is a little hard for a tenor to sing if you aren't used to singing a C5 or above. A good Trivium song to sing would be "Dying in your Arms." Be careful singing Trivium because matt heafy tends to use a lot of distortion and he also does screams too. A cool song to learn by Opeth would be "Harvest" since the Lars has a soft voice in that song.