From Bulbapedia, the community-driven Pokémon encyclopedia.
John Loeffler (sometimes credited as John Leffler or Joe Loeffler) is a producer, writer, and singer for the English dub of the Pokémon anime.
As CEO of Rave Music, he has been in charge of all the music for the U.S. localization of the show since its inception. Loeffler has produced all of the original music for the series, including album releases, movie scores, and the Pokémon Live! show. He has written, composed or arranged a majority of the tracks with the likes of John Siegler, also of Rave, and Norman J. Grossfeld, producer of the 4Kids dub. He, also with David Wolfert, wrote the eleventh season opening theme song.
He has provided lead vocals for:
Profile and Interview with John Loeffler, 2000