After 22 years in the rock 'n' roll business, Steve Winwood still isn't a showman. He's a musician.

For ''Back in the High Life,'' Mr. Winwood shifted his modus operandi. He made his other 1980's albums as solo projects, layering on instruments and voices at a studio on his farm in Gloucester, England. But about a year ago he moved to New York City and started recording with other musicians and a co-producer, Russ Titleman. ''I found that with the advance of technology in music,'' Mr. Winwood said, ''I was spending my whole time sitting in front of computer terminals rather than writing, singing and playing. I thought I should work with people who specialize in programming and computer engineering. ''Also, I wanted to get out of the country situation of working alone,'' he said. ''I wanted to get in the city and get the juices flowing. When I'm in England, I miss America.'' Where ''Arc of a Diver'' (1980) and ''Talking Back to the Night'' (1982) both have a dreamy, floating quality, ''Back in the High Life'' digs into down-to-earth dance grooves, laced with 1960's soul horns and 1980's Latin touches. ''Basically, the music doesn't change,'' Mr. Winwood said. ''The presentation of it changes, the way it's marketed changes, and it's probably a little better technically done, but it always returns to what it basically is - simple rock-and-roll or R-and-B. It's like the internal combustion engine, which is still the same as it was in 1905 - it's just refined and it goes a lot better.''