I had never heard of until last week when I hung out with a friend I'd not seen in close to 15 years. From what I've heard of him so far, he may be moving onto my favorite vocalist list.
Jorn is definitely one of elite vocalists. Very few have pipes that amazing. His work with Ark is his best. Ark's Burn the Sun is one of the greatest Prog Metal discs ever. His tribute to Dio, on which he began working before Dio's passing, is also kind of cool. Here's the only non-Dio track (and the single) on the disc, titled "Song for Ronnie James"...
I had heard of a couple of the bands he's worked with before but never had any interest in hearing them. Now I'm going to have to go out and grab a few of these albums to get started.
I really enjoy Jorn's vocals. I reviewed Out to Every Nation back in the day and it was probably one of the keys to convincing 17 year old me that clean vocals aren't ghey. I still love that album for it's simple hard rock/heavy metal catchiness. I also have Worldchanger (the opening track rules) and the Masterplan debut which I haven't gotten into as much though I plan to listen to them more and try out Ark as well.