How to make up melody for a song ?

[ronz_ombie]

Just check out this girl (Christina Grimmie)
[ Invalid YouTube link ]

So at 0:52, she started playing a melody which is not the same as the song but still fits the song. I'm dying to know how we can make up a melody like that ? Because playing only chords would sound uninteresting !

[starstruck5]

There are many tutorial videos on YouTube -you could start with basic pop and rock vamping techniques -they will show you how chords and scales can be used to good effect -hope this helps -