Help needed for travelling in Barcelona and Madrid

[jazzgal]

Hi all,

im new here and as I was looking up for suggestions/itinerary for spain,
came across this forum and find that most help are being solved.

I'll be heading to Barcelona on the 16 dec and intending to leave Madrid on the 21 dec.
Wish to find out how should I allocate my days.
Barcelona or Madrid should I stay longer?
and where to go, what to do, etc. thank you.