The "hook" of a song

[scoobysoo]

What part of a song is the hook?

[squarebear]

The hook is the main catchy melody that you keep singing in your head. It "hooks" you into the song.

[snagged]

A 'hook' has been defined as a "part of a song, sometimes the key lyric line, that keeps recurring."

[scoobysoo]

Is it usually the chorus then?

[squarebear]

Usually, as the chorus is sung most times and is more memorable.

[Mortartube]

An example might be the lines "Oh we're half way there. Oh-oh we're living on a prayer. " from Bon Jovis living on a prayer.

[saxy_jag]

Mortartube's got it in one - it's that little snippet of a line/tune that you tend to think of or pick up on first. It's the line that sticks in your brain all day and keeps going round in your head. This may or may not be the chorus. Sometimes it can be a riff or a beat, or even an intro or a fill (the instrumental bit between two verses).

Those lines from 'Living on a prayer' are a classic example. I don't particularly like Bon Jovi and I have no idea how the rest of that song goes, but I just know that bit and I doubt I'm on my own there.

[DiscoStu]

The previous answers are all correct but the 'hook' is not always in the chorus, or even a lyric. A great example of this is 'Chelsea Dagger' by The Fratellis. That singalong chant at the start is the 'hook' and the bit that EVERYONE knows. Sometimes it's not even a vocal, it can be a brilliant guitar riff that everyone knows. It's the bit that sticks in your head, like said above!