Rahul Dev Burman (or Pancham, to call him by his nickname) has got to be one of the most influential of all the great Bollywood composers.
His 280+ film composing career is astonishing, you can find his name on the credits of so many Bollywood classics of the 70’s and 80’s.
For a more detailed information on Burman, check out the Wiki page: http://en.wikipedia.org/wiki/R.D._Burman
A documentary on Burman’s life was made in 2008. I’ve not been able to see it yet, I’m sure it will be fascinating.
Visit the website: http://www.panchamunmixed.shemaroo.com/
Here’s some classic soundtracks by Burman.