Complex sentence: The Whiskeyhill Singers, formed in early 1961 by Dave Guard, founding member of the original Kingston Trio, was spin-off from the Trio through which Guard attempted to return to the Trio's earlier roots in folk music.
Split into simpler sentences: The Whiskeyhill Singers was formed in early 1961 by Dave Guard as a spin-off from Guard's Kingston Trio. Guard formed the Singers as an attempt to return to the Trio's earlier roots in folk music.