His name is Jeremy Sweet. He also wrote the "Unleashing the Power (a.k.a It's Coming)" song used in the preview promo/serials that ran prior to the premiere of the Zeo season.
Ron Wasserman (aka Aaron Waters or The Mighty Raw) sung the lyrics to the Theme Song.
If you're talking about The Adventures of the Galaxy Rangers, the theme song was sung by Steve Overland, and it was composed by Phil Galdston and John Van Tongeren.
Jeremy Sweet sung the Power Rangers Lost Galaxy Theme Song.
Ron Wasserman sung the Power Rangers In Space Theme Song.
Jeremy Sweet sung the Power Rangers Lightspeed Rescue Theme Song.
Transcenders/J7 D'Star sung the Power Rangers Operation Overdrive Theme Song.
Bruce Lynch, Marco Marinangeu and Chaka Blackmon sung the Power Rangers Mystic Force Theme Song.
Chyna sang it herself.
The theme song for All That was performed by TLC.
Stephen Hampton and John Adair sung the Power Rangers RPM Theme Song.
Jeremy Sweet sung the Power Rangers Lightspeed Rescue Theme Song.
Ron Wasserman is the one that sung the Power Rangers In Space theme song.
Transcenders/J7 D'Star sung the Power Rangers Operation Overdrive Theme Song.
Bruce Lynch, Marco Marinangeu and Chaka Blackmon sung the Power Rangers Mystic Force Theme Song.
Bill Crawford sang the movie version of the Pokemon theme song. Jason Paige sang the television version of the Pokemon theme song.
Ron Wasserman, also known as Aaron Waters or The Mighty RAW.
Matt Munroe sang the theme song to From Russia with Love.
Chyna sang it herself.
He sang his WWE Song BE MY BABY TONIGHT! HE NEVER SANG HIS THEME SONG! His TNA theme is sung by Dale Oliver.
The theme song for All That was performed by TLC.
It was Johnny O'Neill that sang the Wagon Train Theme Song.