Expert+ is a new difficulty in Guitar Hero for drums only that was introduced in Guitar Hero: Metallica. In this game mode, the notes are the same as in Expert except for the bass drum notes. Expert+ requires an additional kick pedal to play, though the player can play this difficulty with only one. Expert+ is only existent on drums due to songs that feature double-bass playing. Songs that support the difficulty are marked with an Expert + icon.
In Guitar Hero: Warriors of Rock, Ghost Notes are included in Expert+ and they are difficult to hear, but help drummers stay in rhythm. Ghost Notes are required to hit by hitting the drum pads lighter than usual, and they'll score more points. They look like the transparent notes players see on both Guitar and Bass. A few songs will have Ghost Notes, but they come in a rare case. For example, Cherry Bomb has a few Ghost Notes on Expert+.