Look at the etymotics...They are not for everyone but I have yet to get anything but an unqualified "Oh my God" from anyone who has listened to mine. They are unrivaled for traveling as well due to their isolation. They are especially good for Jazz with a special emphasis on vocals. They fit in your ear like a hearing aid and they can be customized for comfort by your local hearing aid shop. I paid $225 for mine. Check out www.headwize.com for more info on headphones and such.
Tony
Tony