Peter Lindgren

Peter did only one project aside opeth as far as we know:

Steel was a formed by Dan Swanö (vocals), Mikael Åkerfeldt, Peter Lindgren and Anders Nordin during the Morningrise sessions in early 1996.
Steel's 1996 demo cassette was an underground rarity until it was finally released by Near Dark Productions as a picture disc 7-inch in 1998 under the name Heavy Metal Machine.