Complex sentence: Formed in 1993, there were up to fourteen of them on stage at any time, and they were principally known for easy listening or lounge music covers of both'classic' and contemporary pop music.
Split into simpler sentences: Formed in 1993, there can be up to fourteen of them on stage at any time. The band is principally known for easy listening or lounge music covers of both'classic' and contemporary pop music.