Complex sentence: Upon completion of high school, he began recording and performing professionally in Seattle, WA with artists including Anthem, The Seales Brothers Band, Redax, Maurice & the Cliches, TKO and American Boys (with producer Don Gilmore).
Split into simpler sentences: Upon completion of high school, he began recording and performing professionally in Seattle, WA. Artists Michael was associated with at this time include Anthem, The Seales Brothers Band, Redax and American Boys (with Don Gilmore).