User blog comment:Sonic The Hedgehog/List of Herbert's Revenge songs/@comment-1405701-20100623142407

Herbert's Theme 2 is when he talks like the:

Duh duh duh duh dun Duh duh duh dun Duh duh duh duh dun dun dun!

Play Herbert's Revenge and any mission with Herbert in it. (Except Secret of the Fur)

And when Herbert talks that's the Herbert's Theme 2.