Complex sentence: It was during this time he began his career in the then new medium of television, spending a few years with KDKA-TV, followed by 22 years as Musical Director for WTAE-TV.
Split into simpler sentences: It was during this time that he landed a job in the then new medium of television. His television career began with a few years at KDKA-TV, followed by 22 years as Musical Director for WTAE-TV.