Those are called parentheses hun.

Sometimes it just looks tacky as in Last Friday Night (T.G.I.F) but it works for songs like Get Naked (I Got a Plan) imo.

It's so if someone remembers a couple words from the song they can have those words in the title so they know what song it is just by looking at the title. Like if you didn't listen to Britney Spears much but liked Get Naked after you heard on the radio, you could go to iTunes, search "i got a plan" and find the song immediately.

Well, I always thought they were just for subtitles. Sometimes that part of the song is more recognizable.

Blow Me (One Last Kiss) is the only I time I can think of where brackets were a great edition to the song title, the rest of the time it's just annoying.

to my knowledge, they are just two different titles put together, based on the Hook of the song.

Cheers (Drink to That)

Cockiness (Love It)

and so i believe while still making the song, and the hook has been created, they refer to the song as Love it, or Drink to that etc. But I'm not positive.

ok well i didnt know how to spell it so i just said brackets

No, you spelled it right.

They are called brackets too