Complex sentence: Guest musicians included Ken Stringfellow of The Posies on guitar, and Nina Gordon of Veruca Salt providing backing vocals on the co-written song "The Softest Tip Of Her Baby Tongue".
Split into simpler sentences: Guest musicians included Ken Stringfellow of The Posies on guitar, and Nina Gordon of Veruca Salt. Gordon provided backing vocals on the co-written song "The Softest Tip Of Her Baby Tongue".