Man, this is one interesting discovery on YouTube. I had no idea what this band Spectrum was all about but looking at that long hair and the spaced-out getups, I just had to take a peek. And what I got was something like the Japanese version of KC & The Sunshine Band.
Spectrum was a band that had a short shelf life of two years from 1979-1981 and it focused on brass-based rock, jazz and fusion. The leader was Ichiro Nitta（新田一郎）who was also the main vocalist and trumpet player on the band, and he led quite the gimmicky crew with those costumes and the fact that he was labeled Spectre (or Specta?) No. 1 with the members following suit with the numbers. I was surprised to find out that Spectre No. 6 was Keiichi Oku（奥慶一）, the keyboardist, since he would also be a composer for a number of singers such as Hiromi Iwasaki（岩崎宏美）.
Single No. 4 (out of a total of 7) was "Sunrise" (June 1980) which sounded more like a supernova rising up from the horizon. Written by Keisuke Yamakawa（山川啓介）and composed by Spectrum, the intro with the brass sounds like something I've heard over and over as an intro for action scenes on variety shows, and judging from some of the Japanese comments I've read on YouTube, it seems like a number of folks were also surprised at the origins. In fact, I read on the J-Wiki article for the band that the song was actually used as the entry theme for an American wrestler by the name of Stan Hansen who found a lot of success in Japan.
Speaking about the comparisons with American bands such as good ol' KC & The Sunshine Band, Spectrum were also called imitators of Earth Wind & Fire, but apparently they were more along the lines of Chicago and Kool & The Gang in terms of influences. In fact, according to that J-Wiki article, Spectre No. 1 stated that his entire life changed when he heard the first track on Chicago's debut album from 1969 when they were called The Chicago Transit Authority.