Complex sentence: Not only has the group influenced other popular musicians but have also been instrumental in creating careers for many, such as Panic! at The Disco, who Pete Wentz signed to his record label, Decaydance Records, in late 2004.
Split into simpler sentences: Not only has the group influenced other popular musicians but have also been instrumental in creating careers for many, such as Panic! At The Disco, who Pete Wentz signed to his record label, Decaydance Records, in late 2004.