The parentheses signify notes that only get played occasionally. For the F#, the 6 on the low E string may or may not be played, but it's a nice way to follow the bass line. You'll probably want to use your thumb for that note. The verse goes: | B E | B Db | Abm E | B Db | B E | B F# | Db | Db :| The chorus goes: | Abm F# | B | F# | Db | Abm F# | B | F# | Db || In the measures with Abm and F#, the F# is only played on the last beat, serving as a passing chord to the B The chorus and solo have (chordiearchive.chordie.com)