Complex sentence: It was in the US Navy that Ace founded his first professional band, a power trio called Sky High (Kerry Henry/bass and Toby Woodard/drums) that performed in Japan in 1976.
Split into simpler sentences: It was in the US Navy that Ace founded his first professional band. A power trio called "Sky High" (Kerry Henry/bass and Toby Woodard/drums) that would perform in Japan in 1976.